I think it's difficult to judge any player on his performances in an Ally McCoist team. You only have to look at the decline of Nicky Law and the rise of Kane Hemmings to see McCoist's affect on the players under him.
That said, I'm not sure Perry covers the positions that we need cover for, unless he can slot in at full back.
Given all the evidence available, Donaldson doesn't have the technique to be part of a Championship squad this season. His versatility is a real plus, and physically he's come on leaps and bounds, but I don't think he's good enough as things stand. Understandably, he wanted regular first team football, and he'd never get that here, particularly if he wants to play centre half.
Today's going to be an interesting one. I think Wednesday night was a demonstration of our 'attacking' system for the coming season. The 4-2-3-1. Obviously the back four remains the same, something that everyone is comfortable with, and that might be why Murray played around with the defence. Against St Johnstone, I think we'll see the 'defensive' system, for use against Rangers et al. I wouldn't be at all surprised to see some variation of a back five, looking at the players we've signed and this new link with Ross Perry. Certainly if it's a back four for these sort of games, I'd be surprised if Craig Barr isn't in the defensive midfield role, rather than at centre half.