I think you are wrong on a lot of fronts there. Belletti came on and went to the attacking midfield role vacated by Kalou, and the moment he is expected to go to right back they score. That isn't his fault, it isn't Hiddink's fault, that is clever Wigan play to exploit the position as the player won't have time to settle. I also recall Belletti starting the move which led to the winner. So it was an excellent move.
Ballack was good. He didn't offer much going forward, but looking at his positioning, he played much depper than Lampard, almost as a second DM. He was solid but unspectacular, much like Mikel has been all season.
Drogba was unlucky with his chances, he had two blocked brilliantly, a third saved and a fourth cleared off the line through excellent defensive play. Anelka only had two, and they were very difficult chances. A header under pressure which was less than a foot wide, and a snapshot from the edge of the area which was saved well.
I thought the team played excellently and it was only brilliant defending which denied us the killer second goal.