No to both Scweini and Muller, actually. I'm a huge fan of both players, but unless LvG is planning to use Muller upfront, Muller is too similar in style to Mata and Kagawa, and we already have both of them in the team. Unless LvG is planning to sell off both Rooney and Kagawa, I can't see Muller fitting into our system. Luxury signing, no doubt, and a WC player, but not for us.
Schweinsteiger, on the other hand, is a different scenario. He'd be filling in for a needed role in the midfield. But he'd be very expensive, both in terms of wages and transfer fee, and it'd be short term, since he's almost 30? He could probably go on and play till he's 35 or so, but I somehow think injuries will catch up to him. However, a vital player to any team, nonetheless. I'd say a 50:50 on this, but definitely leaning more towards bringing in a younger player.