- Heroes in Heroes 3

In the game settings, there's an option for "anti-diplomacy" for creatures. For example, neutrals can be "peaceful" or "aggressive," and I think there's a checkbox that says "never join." Every map has its own quirks.

Added 2 minutes later
And if we're talking about the game, I'm playing as Deso in the Stronghold, Gunar with the Warlocks, Moner in the Conflux, and Tamika in the Necropolis. Basically, my priority is fast units.