Not sure if anyone has tried this yet with War|Maker but I was thinking of trying ‘Bolt Actions’ method of “random unit activation”. Basically if your not familiar with Bolt Action it handles unit activation by each turn both sides put an equal amount of dice (or tokens) to the amount of units they have on the field into a bag/cup. Each sides dice/tokens needs to be unique to their army. At the start of a round one player picks out a token blindly and whoever the token belongs to gets to activate a unit. Play proceeds untill all tokens are next to a activated unit and the round is over.
Rince & repeat