Its a good plan to only use two on longhaul, but the problem is going to be GLA & EMA. When they go tech, you will not have one ready in GLA & EMA, so you will have to position one from either LGW or MAN.
My prediction is going to be, that my companies A300 a/c which the crews complain about always being tech, will no longer be the butt of all the jokes.
Good luck with the B787, because you are sure as hell going to need it.
