I'm not sure that I agree with you here. In terms of mastery, I agree, but I think that there's a lot of technical knowledge which, when you are a learner, has to be learned as theory. Think of learning a language: you learn a grammar theory, don't understand it. Later, you see examples, hear it being used, and suddenly what you previously understood only technically, now you understand practically. I think this is especially true also in music, where technical knowledge usually precedes actual understanding. Whether or not that can be applied to the extent that the other poster claimed ('oh, just sit in a dark room grinding theory for two years, and you'll be a master') I don't know. Maybe he meant what you meant anyway.
In my opinion, if you think you have two good quarterbacks you probably don't even have one. The amount of time that it takes to master an instrument completely is phenomenal. Composition is a skill in and of itself, I don't think pursuing mastery of every instrument would be for (almost) anyone an effective approach. And, I don't know how long you've been in that room studying theory, but like the other poster said you may want to revise your pentatonic scale.