NPC Battle - without killing themselves?
Sorry, no.
Play around with maps, and try to find a layout where the battle's spawn point is near its trigger point, that's the best advice I can offer. And set the battle's difficulty to "medium" ("Hard" battles might include bosses for solo players). IIRC, battles use rescue spawn points.
Eva Destruction AR/Fire/Munitions Blaster
Darkfire Avenger DM/SD/Body Scrapper
Arc ID#161629 Freaks, Geeks, and Men in Black
Arc ID#431270 Until the End of the World
I actually have to fix this in one of my arcs. One side always slaughters the other before the player sees it.
I think I might just make the non-map side some rogue patrols.
I'm pretty sure that if you set something to rogue it'll fight its own faction. So your rogue patrols will fight each other.
Eva Destruction AR/Fire/Munitions Blaster
Darkfire Avenger DM/SD/Body Scrapper
Arc ID#161629 Freaks, Geeks, and Men in Black
Arc ID#431270 Until the End of the World
Most battles you come across in normal missions have two different enemy groups taking mock swings at each other. Is there a way to do this in MA? The only battle option I see (aside from making one group ally) pretty much has them killing each other long before the player even gets there.