You can probably automate some stuff. The ROM-Emulator association is stored in /opt/retropie/configs/all/emulators.cfg. If you already configured some games to start with specific emulators, then you already have some entries there so you can see how its format and replicate it for other games.
thanks! that did the trick :)
i will now try and get all the names of each system and add that into the list!
will try and figure out an easy way to do this now ;P since i got close to 5k roms lol