The Meaning of Life, the Universe, and Everything.
Earth (i think)
looked a little into the mod. since they dont have spawn eggs, or at least i didn't find any, i could only test it out on few mobs. anyway the ai from them was not very optimised since they chased after me even if i was in creative and even after changing my code so i manually set the attack target it did nothing so i don't think it is possible to make them fight. they also doesn't seem to have a revenge-ai so if you really want mob battles with this mod you might have to ask the author of the mod.