Here is a challenge you probably don't want... but I would love to see a system where everything that is resolved by die rolls, whether it be Morale, Commands/Orders, shooting, Melee is resolved on 2 dice added together (2D6 or 2D10, doesn't matter), or possibly 3 dice to get that lovely bell curve. Mersey's LR/PL/R&P comes close except for combat. Could even be opposed rolls.
I've always found it interesting that a lot of smaller model/stand/element/unit/whatever else count games love to use 2 or 3 dice to generate results, but rank and flank almost always avoid doing it that way. I guess having too wide a range of values slows things down.
As for the work of counting out hits, re-rolling them, and counting out wounds, I am surprised that no company has made dice that combine color coding with the pips to make them easier to sort. Something like the 1 is red, 2 is orange, 3 is yellow, 4 is green, 5 is blue, and 6 is violet or pink or silver or something. I'm sure alternatives could be developed for color-blind players, too. I know some people have an easier time sorting by color than by number, and "remove the reds and oranges" might be easier than "remove the 1s and 2s."
One thing that often happens in the Kings of War community is that if a particularly nasty charge is made that would result in rolling enough dice to potentially remove a unit from the table, players will often agree to simplify things. I know when I once goofed and left a unit open to a 48-die rear charge from a unit that hit on 4+, I did the mental math and realized the only way I'd survive is with a roll of 2 on the nerve check. I told my opponent they could just skip to that since the odds were astronomically small of my unit surviving and I just wanted to keep the game moving.