100 dice!! I think you may have reached overkill levels of dice-throwing already :) Here’s my suggested breakdown:
20 “ones”
40 “twos”
30 “threes”
10 “fours”
This would represent a perfectly-matched battle with a unit count of 40-50 and the following composition on each side:
20 inf/art in any combination
15 tnk/ftr
5 bmr
I think that breakdown would cover 95% of your battles, with a possibility that you have to throw some infantry dice twice (or throw a few of them into a “2x” or “3x” tray).