As to the PC7 versus the Tucano, the Tuc would win hands down IMHO. The PC7 has about half the power of the Tuc. It's the PC9 which is the Pilatus equivalent of the Tucano. A lot has been mentioned about the comparisons, but they are essentially very similar aircraft. I've flown both and there is little to differetiate them.
I'd argue that power is a fairly small part of the equation defining the quality of a military training aeroplane.
G