For those who really like to roll dice, I'll offer this simple change: rather than multiplying the result of your attack dice, just add the unit's attack for each tray facing your opponent. For example, if your have a spearmen unit with three trays facing an enemy, you would roll 3 blue dice and 3 red dice.
Just wanted to put that out there for people who really like rolling dice. Not quite a bucket of dice but you can always play the Imperials in SW Armada for that!