[sector24]

If you don't mind exploiting a bug, forge a crystal matrix for a holy priest (with no other paths, only holy). Group him with at least 2 astral mages scripted to cast communion slave. The priest will banish 3 times per round instead of 1. This is very easy for Bogarus, and the more slaves, the bigger the banish.

In a more general sense, you can't beat Ermor with troops. You have to use magic, either large amounts of conventional mages with troops as blockers, small communions to cast battlefield wide spells like Solar Brilliance with expendable chaff to block, or a global like Purgatory with lots temples and dominion spread. (Is it Purgatory that blasts undead in your dominion? I don't remember). Fighting Ermor with troops is always a losing endeavor for two reasons:

1) Their troops are free
2) Their mages spam raise dead in the backfield, so you're actually fighting an army about 50% larger than the listed number.