@dudleydes Thanks, I've already made the two new systems by making custom collections. but I need to remove the old ones. It looks like Emulation Station doesn't allow you to remove a system from the carousel. If I remove them in the es_systems.cfg, the roms they are attached to also disappear from the collection.
It used to be that you could do this - https://retropie.org.uk/forum/topic/10849/create-a-custom-es-system-able-to-launch-games-for-many-systems -
but collections are the new hotness.