Utter bollocks. The main effort will always focus on people, therefore unless people have started to live at sea or in the air, the land domain will be the main effort in the majority of cases, even when larger air and maritime enabling functions are required. Don't tell me, I bet you think the army should be a projectile fired by the RN. As to cost, I don't have the figures to hand, but I would point out that in capital equipment terms at least, both the RAF and RN are vastly more expensive than the army. Of course in reality any direct cost comparison in terms of cost versus capability is likely to be meaningless as you'd be comparing apples with oranges.