Defensively, the Raptors will be fine. I mean, nobody is going to stop Golden State when they have six All-Stars on the team but Toronto has as good a roster to slow them down as anyone.
My big question is whether the Raptors can score enough points to stay in the game - especially given how poor their outside shooting has been since the playoffs started. Kawhi will pretty consistently get his, but after that it's a bit of a question mark where the points will come from. If Danny Green's shooting finally reverts to mean (ie: he gets silly hot like VanVleet was last series, to make up for the terrible percentages since playoffs started) then the games could at least be fun to watch.
However, I'm not sure that I agree with those defensive assignments. I'd rather see Leonard play as much on-ball defense as possible, and Klay's average time of possession is tiny - catch, shoot, rinse, repeat. Put Green on Klay instead. Also, I'd rather trust Lowry/VanVleet to check Curry as primary defenders and let Siakam roam a bit on defense by assigning him to someone that isn't a lights-out shooter (ie: like Iguodala).
Also, it's hilarious that being "short-handed" for the Warriors means they can only start four players with a history of being consistent All-Stars instead of having 6 available to choose from. (Yes, Iggy was a perennial All-Star and remains an excellent player. He's clearly past his prime, but still darned effective in his role.)