I agree with the thread, BTW. And Ezio doesn't scale to Altair's feats, BTW. That's 'cause he has his own Wall level feats.
Ezio can easily tank sledgehammer strikes to the face without issue and take full-powered axe slashes from brutes and almogavars with zero armor (proven in AC Revelations), both of which should be Wall level, since they're swung real fast by the enemies with just one arm. He also tanked cannonballs in AC Brotherhood, more specifically, Sequence 9- Memory: Pax Romana, just after Cesare leaves, Ezio is struck by a volley of cannonballs and was only knocked unconscious (here: https://www.youtube.com/watch?v=lVhj352bXQY#t=00m43s ). Ezio can also tank his own bombs, AFAIK, and he can jump from heights high enough to grant him at least Street level+ durability if not higher. The extra bulk of Ezio's equipment gives him more mass and the result would get bumped up to Wall level anyway and the armor doesn't stave off fall damage in any way, so remove the armor or not, fall damage always takes the same amount of health (But the feats above already explain why he should be Wall level). In the beginning in Revelations, he also falls from a significant height as seen here, and he clearly shatters the wooden platform and walks like nothing happened: https://www.youtube.com/watch?v=c1Vo3hYt_is#t=2m40s
Now, comes his physical strength. He can effortlessly break bone and snap grown men's necks, and the latter part is Wall Level as far as VSBattles and this wiki dictates. Not only that, he can easily defeat enemies in plated armor without the metal cestus and deal severe damage to them as if the armor wasn't even there, something not even the strongest athletes have done in real life without weapons, and mind you, their armors are strong enough to take sledgehammer blows from Ezio himself. Ezio is also strong enough to swing around a sledgehammer multiple times in quick succession like it was essentially massless with just one arm (Like, what the fuck is even going on here!? XD https://www.youtube.com/watch?v=tJ35PQ8AAUg ). And of course, there are the janissaries, Shahkulu and Tarik Barleti, all of whom have much tougher armor than all the other guards, and Ezio can still draw blood from them and even wittle them down to dead bodies (Ezio killed Tarik in a fist fight instead of an aerial assassination in the novel, with Tarik having 3 times the health of a janissary, and Ezio noted Shahkulu's armor to be too thick for bullets, and even when Ezio performed an air assassination on him, Shahkulu just got up, started to strangle Ezio and threw him aside. Then you can proceed to kill Shahkulu unarmed, and he then dies, just like that.). Then again, the guy (Ezio) can kill heavily-armored guards with a broom and swing sledgehammers as fast as a sword, so who am I to judge? :P
Mind you, Altair can do the same exact feats and has the same exact durability feats as seen when he escaped Masyaf with his son Darim. A couple of rogue Assassins were equipped with warhammers of the sort. Not only that, he could also pierce and cut through chain-maille in Assassin's Creed 1 and in Bloodlines, where he kills Armand Bouchart. He could also pick apart at armored enemies with chain-maille with his fists too (it's lengthy because they parry the punches with their hands, but yeah, once you get past them, it's a matter of button mashing before the enemy's down and out for the count). And of course, there's the Moloch feat as seen here: https://www.youtube.com/watch?v=jrgqec2sNJ8#t=06m16s
Oh, I forgot. They can both draw blood from horses with their hits (Ezio can do it regardless of whether he has the metal cestus or not). And Ezio was also seen to slice men in half easily with his sword in the Assassin's Creed: Reflections comic.
Now, onto Edward Kenway.
He literally has most of the same feats as his son and grandson. I believe he was supposed to be upgraded via this thread which mentions him tanking swivel cannon shots which bypass the Mayan Armor even (yes, you can survive them even with the base outfit which is considerably weaker) but it never went anywhere and was later shut down by Ant: https://vsbattles.wikia.com/wiki/Thread:1165123
Not only that, Edward has survived massive explosions consisting of massive gunpowder barrels you see on ships, and not only that, he can easily tank the bite of a jaguar and nonchalantly kill it, as if nothing happened to his arm, and the gauntlet does nothing to stop the jaguar from biting into it. Edward can also tank grenade explosions at point-blank range without issue, just like Connor and Haytham.
Striking Strength wise, Edward can also beat up bull sharks so hard they swim away in fear (Just like Batman beat up a great white in Arkham City). Edward Kenway can also send guards flying several meters with a single kick and shatter wooden furniture and barrels with his blows, just like Haytham and Connor. Edward even kicked down a large fortress door in his search for Laureano Torres. Also, shouldn't Edward receive Class 1 lifting strength for overpowering an American crocodile (Males are usually this heavy: 400-500 kilograms)?
And Connor's durability should be upgraded to Wall level+ and have this description: Tanked cannonballs during the Battle of Bunker Hill. Survived a shed full of gunpowder exploding beneath his feat. Because during that mission, I waited for the cannonballs to hit me, and they did, they took out a large portion of my health, but still more than half of it remaining. And the gunpowder shed is just that, him tanking a gunpowder shed exploding (although it reduces your health to almost zero). It happens when you blow up the cache reserves of the forts you conquer for the Patriots. There's also a feat in the Oak Island Mission where you blow up a hole in the island to get to the Money Pit, and a huge amount of stone is blown up. Connor can also survive that should you wish to, although he would barely survive that. Don't worry tho, if you're in the epicenter, he'll fall into the water and heal back fast.
Now, in the case of Haytham, Connor and Edward (due to sharing the same game engine and movesets), all of them can effortlessly snap necks and break backs in normal gameplay. They even tore apart metal locks with a single punch (you know, when you try to save prisoners from pillories, here's the proof: https://www.youtube.com/watch?v=tjYUC7-fvRs ), something even the Barrett M82 has a tough time doing, and it can pierce walls. Not only that, Edward Kenway has also at times smashed apart chest locks when you dig up buried treasure.
And of course, how could I forget? They can all trade blows with and easily kill those who can harm them in a fist fight.
All in all, all the protagonists should be upgraded to Wall level.
Combined with the fact that Ezio can swing around sledgehammers with just a single hand, he should also get "At least Peak Human" lifting strength. Because I have no idea how strong you'd have to be to treat a sledgehammer like a toy. :P
EDIT 2: Oh wait. Armors and the armor upgrades in AC1, AC2, AC Brotherhood and Revelations and the later games also do nothing to reduce the amount of fall damage or any kind of damage anyway (it's just there to prolong your suffering in the games :P ) as we can see the guards still being visibly strong enough to draw blood from Ezio (with the latter equipped with his strongest armors) and vice versa. The same is true for all the games in the series.
EDIT 3 (the final one, hopefully): Does it seem bothering that every single protagonist in Assassin's Creed can effortlessly climb hundreds of meters without any adverse effects to their health and jump several meters from one ledge to another consistently without any issue? (Video game logic, I assume) This feat should also be in their profiles, which will affect their lifting strength further. Stamina remains unchanged, although Ezio's stamina description is not yet completed. It should have the following, I believe: "During the Siege of Monteriggioni, he survived getting shot at multiple points of his body and falling from a significant height at the same time and still managed to later on fight and blitz several armed guards without issue, later on freerunning throughout the Auditore crypt, and in the ensuing conflict, not once did he suffer from exhaustion. Even though his arm was numbed out due to the antics of his carriage fight with Leandros, he was still capable of non-chalantly killing off all his men with ease. Even in old age, he managed to overpower several heavily armed Chinese men with only a fireplace poker and managed to do immensely stressful acrobatic maneuvers"
Apparently Edward has another Wall level feat. It's extremely difficult to do so, but you can do it.
From the Assassin's Creed wiki, it says this:
It is possible, though difficult, for Edward to kill El Tiburón through other means than just pistols. However, he cannot be disarmed, knocked down or harmed by darts. The game may glitch and allow a regular counter as if he was attacking with another weapon. This can be used to disarm him.
And it checks out. Very rarely the brutes in the game will perform an attack that you can easily use to disarm them. Once disarmed, the brutes essentially have no resistance to fists, and you can take them right out. As is the case of Edward's fight with El Tiburon. To exploit this more, you can use trainers via the "Constant Stealth" modes, and it doesn't alter your physical stats, but even then it's hard to do so. And the guy's armor is thicc AF.
Sorry for bothering you, Luffy, but it seems the upgrade thread's gonna be a lot bigger than I thought. Please forgive me if I disturbed you. :(
Every single protagonist in the entire game series can casually stab clean through skulls, twist their heads a full 180 degress even (At least in the case of Altair and Ezio) and then cleanly pull the blade out without any issue at all. This is more evident as seen when you use Vlad Tepes' sword in the game. I don't know how significant that would be, but I'm sure even peak humans would find this tough, as seen here: https://www.youtube.com/watch?v=wD1MYWU2Leg
So it's from the Oak Island mission in Assassin's Creed 3. Connor shoots a couple of gunpowder barrels and it blows up a huge amount of stone and a hole into the island, giving Connor access to the Money Pit.
Now, if Connor were to be desynchronized, his body would enter ragdoll mode, but seeing as he falls down like this, he survives.
Considering the fact that both Haytham and Edward Kenway can survive explosions of the same level regularly in the game, and that sure explosions like this generally yield Wall level+ to Small Building level, they and Connor should have their durability upgraded to Wall level+ (assuming Haytham ever gets a profile, LOL).