Talk about contestants I don't know anything about.
Anyway, modern flamethrowers have an effective range of up to 80 meters IRL and were amazing close quarter weapons, which made them widely used in trench warfare.
Blunderbusses failed as military weapons back in the 1800's because of their incredibly short range and innacuracy. Think about it: the blunderbuss was considered a failure in a time where guns were still fairly primitive and innacurate.
In a blunderbuss vs Flamethrower fight, it is obvious who wins.
That said, the cannon could
maybe give K.Roll a chance, seeing those have a range of up to 1.8 killometers. But, unless he has Falco's sight and Kirby's luck, he is not going to hit anything with it.
I say it is obvious who wins.
BTW, I was about to call bull**** on Cloud vs Crono, but then I remembered that Cloud got grenades and machine guns, and then I disregarded what I was about to say.
Also, we need to fit Leon in some way or another.