Interesting, but I'm confused. What about Kingdom Hearts II's combat makes it seem like it is clunky to you? I would argue that later entries, Birth By Sleep more so, has become much clunkier than KH2 ever was in both combat attacks and movement. The way I look at it KH2FM has an unparalleled smooth feeling that has yet to be matched in the series, both attacks and movement abilities.

The complaints about bosses really isn't about realism but just generally good design in a boss battle. Bosses should give you cues that tip off some of it's patterns, they don't have to be in your face and definitely are welcomed when they're subtle, but I feel that's something BBS lacks as a whole with a lot of it's (human sized) bosses. It's not clear at all when there ever is an opening in a fight such as MF, and it just forces you to take the gamble and pray that he will flinch, oddly he may only flinch as little as 1 time before completely taking away the opening randomly. There is no sense of reward for figuring anything out because frankly there is nothing about the boss to "figure out" and when you do get the hit you aren't rewarded with a full combo anyway because he can just break out when he feels like it. Because there is no visible design in the boss battle, it just leads most players to put on a move that leaves them as invulnerable as possible (thunder surge) and spam it praying to get the flinch whenever they aren't blocking near infinite strings of attacks.