um, everything? It will effect your club path, angle of attack, possibly clubface all kinds of stuff.
sounds more like you have a path issue and not a turn issue. Your arm plane should not mirror your turn beyond a few feet. You will be fighting the kinetic chain if you use your arms before the body.I've been trying to think 'more arms, less body in the backswing' to get more upright and avoid being too flat in the backswing - in order to fix an inside out path on the downswing.