Tigers is a bit generic, but so is Rebels. And I really don't think it fits. Rebellious is not a word that describes Canada's past well. oronto Rebels could be in the discussion, but certainly not Upper Canada Rebels. Calling it Upper Canada doesn't make it more Canadian, it makes it more Ontarian...which may even be kind of annoying to some other parts. It should stay Toronto.
I strongly believe that it's almost always best to use the city's name. There are exceptions, but they usually make sense..
-Utah, Indiana are partly the city names are long, but it's also clearly partly because they're the only major cities in their states, and so it isn't pissing anyone off too much
-Golden State was taken to avoid any controversy when the team moved to across the bridge to Oakland. And I mean, now they're on schedule to move back to San Francisco.
Anyway, I would also take Bandits over Rebels. It doesn't seem to fit either, but hey, we stole half a continent from the native population, so Bandits fits better than Rebels. And nothing better symbolizes Toronto's wildlife landscape than the Raccoon.....for better or worse.