If the DamageAtBone (by radius) was coded in the player melee weapons and set to true/false in the weapon.ini,he could reach further berore they catch up with him and slash at wider areas.
Use a custom player skeleton with bones fitting various types of weapons like dagger,polearm,flail.
Since i think the melee attack animations dont adapt to look up/down motions,i assume that to hit a very short monster you would have to crouch-or have a large enough bone damage radius.