So Rommel is head of OKW? When?
Well, firstly, this does not change much. Despite the theoretical command structure, OKH effectivly ran the eastern front as it's own little fiefdom. So Rommel is in effect going to be running the western front, and that's it. And Hitler is probably not going to want to change that, as it had been his policy to keep various administrative and military commands divided and competing.
But I dont think that Rommel becoming Generalisimo of the german war effort is going to be enough to win it all. He was a good tactician, but his strategic vision was not particularly strong. And he was a gambler as a commander, and it is easy to see him risking to much on one last offensive.
as for Galland, I dont think it is war-winning, but almost anybody would be better than goering.