I don't think Wenger is instructing Ramsey or anyone else to do anything, he very rarely does the way it looks to me.
The second half against United was a perfect example of that, think it was Gael who said it that we had three players in Cech, Bellerin and Monreal where you could tell their position apart from the rest, everybody else was moving wherever they pleased. Ramsey was hanging on LW for a good while, Alexis played DM, Welbeck was everywhere and nowhere and Walcott presumably somewhere in the stands.
It would also go a long way to explain why our players rarely seem to recover during games because there's no instruction from the touchline to get back into position or to just concentrate on doing your primary job. Ramsey's head was in the clouds, he barely got to CM to pick up the ball the first thing any sane manager does would be to rein him in or sub him off.
I've said it before, Wenger's usual approach works with players with high game intelligence and/or loads of experience. When we don't have guys like that we're overreliant on players hitting peak form and carrying us for a number of games to get the points.
