I did saw that from years ago there was a mod of Gang Garrison 2 that adds in a bunch of new crossover classes into the game and it was available at the Gang Garrison 2 forum and then it was removed at a unknown period of time and I can't find it with a search.
So if you had played this mod before please acknowledge the name and information about this mod and if you still have the files of the mod please provide a download link of the mod here.