Honestly I don't think this is that far from the real deal. These weapons are clearly heavy and I am pretty sure taking one of those voulge swings to the head will fucking hurt. Of course people don't die as quickly, it is a very cramped area and neither side is actively trying to push. This makes the combat look rather stale and uneventful, but apart from that, the way people are swinging, the way people are protecting themselves and others, think it is pretty close.
Of course one needs to differentiate between different era's and army types. I think the early feudal armies which consisted of levies with little training, would probably only be commanded by telling them to hold or charge and then hope for the best. I think it would be a chaotic clusterfuck, although naturally people will try to keep friendlies at their sides and backs, unlike Braveheart where everybody seems to be fighting alone against charging opponents from all directions.
Professional armies which have been trained and equipped to actually hold formations, like hoplite phalanxes or 15th century shot and pike armies and everything after that, would probably cause a much less chaotic melee, with clear lines, trumpet signals and officers keeping everyone together. I honestly doubt Roman legionnaires would hold much of a formation though, as it was supposedly fairly loose and would probably get fairly chaotic if charged.
I find the idea of pushing matches ridiculous, people try to kill eachother, not move eachother. I think early medieval and viking shieldwalls were a method of keeping together before combat and during combat it would either dissolve or people would hit over the shields during combat. Same with phalanxes, they would be pushing with their spears or pikes and not with their shields. Lindybeige's suffocation argument seems stupid to me as well, if their chests do not even have room to expand because they are packed so tight, where did they leave all their sharp weapons? Such masses of meat is not something I find logical, I think fighting would be generally somewhat more spaced out because I think people tried to use their weapons to fight.
