Invastion of England House rules for Black Powder

So at Huzzah I am running a game using Black Powder rules but I have made some minor tweaks to address two situation I don't like.

The First is Disorder from musket fire.  Every time some one rolls a 6 a unit gets disordered and often frozen in place for several turns, that seems unrealistic. Its also frustrating for players.  So musket fire will only disorder if the firing player roll two or more unmodified 6s for a unit. Artillery will still disorder on a single natural 6.

I am also modifying Melee combat as I have seen multiple games were two units are locked in hand to hand fighting for turn after turn after turn. My reading on 18th century war tells me most close range fights were short and sharp with a winner decided fairly quickly. 

So each unit will have a hand to hand value of 4, 6, 8 or 9.  That value will be added (and some modifiers) to a the roll of a d6 if your total is higher then your opponent's total you win and he falls back(one move) suffering two casualties while you take one casualty. 

Ties are a win for the defender. 

If you get total greater then twice what your opponent got he takes 4 casualties and is disordered while you take one causulty.  There are no saves for Melee casualties. After the loser falls back conduct any break tests and apply the results at that location (ignoring any comments about combat continuing).

This is almost an exact copy of the melee system in Maurice modified to fit the Blackpowder game  system.

Comments and suggestions are welcome.