I agree that Mac was Guardian, and consider his death to have been the first of a long line of blunders in handling Alpha Flight.

While it is difficult to see anyone other than Mac wearing the suit, he has already been resurrected to the point of nausea. The damage has been done. And the only true repair would be an Ultimate Alpha Flight ... which would also be the ultimate repair of the mess they made of AF over the years.

Outside of that I would prefer if no known character wore the Guardian suit and it's Mapleleaf sheath. I would rather see a fresh face. Some patriotic top cop or decorated soldier, something like that. Major Mapleleaf Jr. migth have been good in the suit, but he dead, ain't he?