Well, I don't know how this mod is structured, but if it were possible to play without mixed units, there would be a special .pak file for that.
Why is that?
Because mixed units are usually not generated; they are defined in the map, although there was a mod that did this with a script, but it was a long time ago, and it wasn't entirely true.
If I'm wrong, I apologize.
Thank you, that's a shame. The mod is very good, but these mini-armies are very annoying. I thought I could find it in some .lua file, but alas.