From the latest War Room update:
we are going with this rule for FA: “In Surface Battles only: blacks and whites are misses for the side with fewer Surface Unit Types”. Why? It is simple. While in the more extreme cases the math doesn’t deliver perfect equality, we believe after much testing that it is a strong enough incentive for a player to really try to bring multiple types. All other other ideas that we tested were too bloody or too fiddly to resolve. We’ve changed to Orange Zone Penalty to not involve black dice but rather reduce Orders by 3.