From a tactical perspective, lowerin our line would be a natural consequnece of the change in attacking focus. It does look like we're going for pace and directness now, more than creative 50 passes or death sort of stuff.
A high line is essential for tippy-tappy, as I've read people call it, possession football. But it can work against you if you focus on directness. By compacting the other team, there's no room to run in behind, and by meeting the opposition high up the pitch, you don't get the chance to catch them on the counter as much.
I don't mind getting Mertesacker, I think he'll be a good option to have. Still think Vermielny is our first choice pairing.