Firstly I suggest to add weapons that damage would depend mostly on character's agility like flails, quarterstaffs. It would be more defensive combat - dodging and parrying.
Secondly I think there are to little fish in H&H. I think there should be added more of them like:
-barbels
-chubs
-grass carps
-carps
-cods
-crusians
-ruffes
-rudds
-lake trouts
-burbots
Update
I figured out how it would work. There will maneuver Mantis stance (Whatever). While active it will provide 100% chance to hit a foe while he misses. There will be also a slight chance to parry foe's attack and hit him.
Formula for damage dealt while parrying and foe's missing: √Intelligence*√Weapon's quality*√Strenght*√Melee combat skill /√Foe's Constitution*√Foe's Psyche
Example: √20*√35*√40*√60/√50*√15=4,5*5,9*6,3*7,7/7*3,9=47,2 damage
Formula for chance to parry: √Intelligence*√Psyche*√Strenght-√Foe's Intelligence*√Foe's Strenght*√Foe's Psyche
Example: √20*√15*√40-√25*√45*√10=4,5*3,9*6,3-5*6,7*3,2=111-107,2=3,8%