not sure what wobbly effect you are talking about? The way they wiggle their hands right before the attack starts is kinda a glitch, extra forces get applied to the limbs during an attack animation and it causes the fists to overshoot their target in the pullback phase.
The dismemberment is based off this Unity script I found: http://www.idlecreations.com/loz/chopScript.cs but with quite a few optimisations and fixes.
Thanks for the love! Hope the game will get even better!