I don't think we have to worry about General Pace putting the Marine Corps' agenda ahead of anybody else. The Marine Corps has been making do with less than any of the other services since its inception. Even though we are part of the Department of the Navy, history shows that on many occasions, the Marine Corps has been treated as the bastard step-child and has been tried to be shuffled into the Army on several occasions. Ironically, the US Navy itself has been a proponent of such a restructure in the past. Many senior Naval officers saw the Marine Corps as a leech to the Navy's budget. They'd rather have spent more money on their blue water, aviation, etc. capabilities than a small force of troops that were outgrowing their limited role as force protection for naval vessels. It was through the work of Marine Corps officers, not Navy officers, that the Marine Corps's place as a separate service, albeit smaller in scope to the Army, Navy and Air Force was reaffirmed on several occasions up into the 1950's.
The Marine Corps is always asking itself, "Why do we need a Marine Corps?" If we find no relevance, then we should be abolished. We haven't found that reason yet and I would venture to say that it will be a long time before one is found. The reason is that the Marine Corps is an extremely fluid organization, capable of adapting itself to new missions and embraces the organizational changes necessary to accomplish those missions somewhat more readily than the other services.