Random Monsters Map Patcher – diverse neutral armies.

Negative Battle Damage (BD) is also interesting. It definitely won't be low. You could reduce the chance of such stacks appearing, if that's what you want, otherwise, the variety will be lost.

Negative Battle Damage is very bad. Why give the player an advantage that doesn't need to be given? Skipping each turn has serious consequences; it's essentially a freebie (to a much greater extent than morale triggering on your own troops). And all this without the player putting in any effort. In reality, sufficient variety is achieved by mixing just 2 factions; 3 or more looks like a mishmash.