The point about Armitage (and Pocock, Cooper, Tipuric, Warbs indeed any decent openside) is that they can link and play out wide with the ball in hand – none of our Flankers currently appear able to do that at international level. Launchbury looked better with the ball in hand.
AA is right you can of course construct a game plan that just relies on big back row smashing it up (as we used to) but that’s never been particularly successful and getting less effective as the professional era moves on. Haskell’s never been particularly effective at the international level because just hitting it up and making hard yards doesn’t cut it against decent opposition. 2003 was the only time we had an all round game.
On the subject of turnovers of course it’s not the seven’s job to prevent them – that’s a whole team responsibility but he should be the best placed to make them if his lines of running are half decent.