I had developed shifters differently. It would be family pathes that you could choose. like choosing feline, avian, fishes,...
But anyway, It's a good idea to have stronger than normal forms (some benefits) if you have more of a specific family. One with four felines, should know them better than anyone else, so he'll have a stronger tiger than anyone else. Also make it give some goodies to those who choose same pathes as minor/major. air/air, should make your forms stronger again. This should happen for all other classes too (off/off=better off, def/def=better def and so on).