>>324923480
You basically have two ends to the melee combat spectrum: Full physical simulation (B&S, Boneworks, etc.) and Hand movement as a way to input abstract attacks (Until you fall).
You sound like you want to end up at the abstract end of the scale - decoupling the character's battle prowess from the player's.
>the player needs to keep swinging which may get tiring
Kinda unavoidable in vr. Either pace encounters appropriately or add long cooldowns to attacks.
> it seems immersion-breaking if enemy strikes rebound off empty air
Pic related. It's the beat saber block's hitbox. Way off, yet it feels great. You'll have to experiment, but there is no need for things to be "correct" in order for gameplay to feel right.