I, for example, create an emulator called Neo Geo System and link it to M.A.M.E. In the romlist of this system I load all the corresponding games such as Fatal Fury, Metal Slug, etc. Then, I create another one called Capcom Play System I and link it again to M.A.M.E. with their respective games and so I do with each one except Naomi, Atomiswave and Taito Type. This method is what I use, maybe a bit complex, but I like to have a more exact order.