I wasn't sure about the feasibility of authentic FP sword combat either and I'm still not sure. It did work much better than I had imagined but I'll be lying if I said I don't have much more fun with more arcade-y combat like Dark Souls.
On the other hand an action-arcade combat like that would probably look weird in an authentic game like KCD. Tough call.
The issues with the combat system have nothing to do with realism (of which it has very little...The guards, and some techniques like a half-sword thrust... Not even available with the longsword but only the arming sword or whatever it was, and at the end of one of those useless combos instead of a mode-switch), imo.
It was just a poorly designed system altogether.
Everything from how exactly the stats influenced stuff (which can be done much more sensibly via affecting speed/strength/recovery/thrust accuracy and such instead of stupid perfect block/counter chances of both you and the enemy), to the dumb-ass console-game like combos, the perfect blocks, the controls/camera... Lock-on etc. Very console-y imo, just first person.
No real footwork and weird movement that make your guy feel... Floaty and sluggish. Slow-ass delay on attacks. Can't do a quick thrust to catch the other guy in the visorless face... Henry needs to first telegraph the fuck out of his attack, meaning it always gets blocked unless you win the diceroll or the enemy glitches.
Hell, targeting also sucked.
The damage system is also nonsense (unless they changed it since I played). You/enemies take damage after stamina is depleted only (except arrow damage?).
The weaponry was very limited/not properly implemented (polearms).
Also no grappling (crucial part of melee combat) aside from a bit of clinching.
I'm kind of bummed that so many (esp. elsewhere) seem to think that the attempt at realism (such as it was in terms of the silly combat system) was the problem here.
A real life beginner can fight better than Henry (and especially move much faster) with a few months training, tops.
Combat system/implementation was the biggest flaw in the game for me (well the bugs/performance second).
On another note, I wish we'd been able to change more about our character's starting skills. What the hell did he do all his life? All you get at the start of the game is +1 or so to some stats depending on whether you say you slept with the tavern chick the previous night or whatever.
Why couldn't he have been part of the local militia/guard, start with some basic gear and combat skills?
Maybe he actually learned some smithing/maintenance from his dad? Nope. Or at least only barely.
Worked as an apprentice for a hunter? Nope.
Work in the silver mine? Nah.
Nada.
At the age you start the game you'd think Henry wouldn't be such a near-blank slate, or was it customary in that area at that time to raise your kids as useless NEETS?
Hell, you'd think Henry would know how to wrestle at least.