I feel like that is a pipe dream and won’t ever happen in any large numbers. Fighting is too wide of a field, unless you are training since practically birth in MMA you will just be mediocre at everything. You need to specialize and become a master at a certain aspect of fighting and use that like a backbone to branch out. To my knowledge besides Rory Mac no fighter has taken this approach and reached the top of the sport and even he never became champ. MMA will always be filled with experts from other fields transitioning to the sport.