I only kept one domestic cacatuoides. I used to get the fish directly from the boxes as they arrived from Peru. That's why I saw such a variety. I just assume with Apistos that you have one species per tank, and a few fast dithers/distraction fish up around the surface. They never got much of a chance to pick on other species here.
It's going to be a good thread. Apisto fishrooms are great fun. I'll risk a short sidetrack though - do you think Apistogramma are making a comeback? They were big at the turn of the century, and for the last 10-15 years have sold very poorly. I used to unpack at least 4 shipments of cacatuoides a year, let alone all the other treasures coming in. Now it seems importers here have given up on them as the linebred ones have muscled wilds out of the market. When they order them, no one buys them. It's a shame, and I've long hoped that would change.