If we get a new C then I am totally fine with benching Williams and Brewer. No doubt. But we do know rebounding and defense will be issues, and in the playoffs against CHI & BOS we're going to need just that.
Make the newbies feel welcome. Like in baseball when you call up a kid from the minors... get him in a game and let him get his feet wet, or else rust starts to accumulate.
We know Douglas is banged up and inconsistent. Walker and Williams sort of offer the same thing... I think Williams is a definiete need, b/c Turiaf gets injured a lot. So, if we dont get a center and Turiaf is hurt, suddenly we need Shelden.
PLUS, does Fields really need to play 43 minutes?
Same issue might arise even if we trade for a big man. He probably wont play. Carmelo, Stoudemire and Billups will (and should) be on the court for 35+ minutes. It's the pieces we run in and out around them that will change.
My complaint with MD's 8 or 9 man roation is this: He prefers shooters over size. Douglas plays solid defense. With Williams we probably don't need Brewer. It's just the size thing to me. Not that Williams is Ewing. It's just what happens when Turiaf is out?