If Mussina can come back, I would go with Johnson, Moose, and probably Wang and Wright. I know Small and Chacon would be very capable out of the bullpen and be able to eat up innings. I'm still undecided, because Chacon's last couple of starts looked a little shaky. If we get all the guys back and healthy that can be back, I go with Johnson, Mussina, Wang and Wright. If Wright or Wang is ineffective in a couple of starts before the playoffs start, I switch them for Small without a doubt.
If Mussina can not come back effective, I think I keep Small in the rotation. I go with Johnson, Wang, Wright and Small.
Although I do see where you are coming from with your rotation, and really would feel confident with all four of them starting I just don't think Wright will be able to provide much if anything out of the pen, and I think Chacon could be a huge help out there. And if Mussina does come back, I think they need to slide Small into the pen as well to eat up innings. Even though he can be better than Wright and possibly Wang, I think he's more versatile.
Somehow, I think that Sturtze will not recover, and Chacon will need to take his place in the bullpen. Just a gut feeling.