I can't imagine having that armor on and actually trying to do something in it. Much less something as physical as a prolonged battle.
The problem with armor was most likely overheating rather than weight. Good armor was remarkably lightweight but one wore a protective layer of heavy clothing under it. Judging from the head wounds on his remains, Richard most likely removed his helmet after dismounting from his mired horse, possibly because he was overheating after having just taken out two opposing knights in combat.
Overall though, IIRC the dynamics of medieval battles are still uncertain. Even today highly trained athletes can't flail around with hand-held weapons for extended periods of time like they do in the movies. Plus staged modern-day melees involving trained swordsmen would have been so lethal with real weapons that most everybody involved would have died or gotten maimed inside of the first two minutes.
The gist seems to be that actual combats were swift and deadly, over in seconds, just like successful gunfights today, and presumably one avoided fighting fair whenever possible.
How do you rate this last trip compared to others you have been on?
The Isle of Man with my son followed by forty days on a bicycle?
Hey, in a league by itself
