Okay I've figured it ALL out. Mario is, in fact, sronger than Luigi. The reason his tornado doesn't do as much damage as Luigi's cyclone is because he's not giving it his all (take a look at his face while he's doing the tornado- no strain at all!). The reason for this is probably because if he WAS giving it his all, he'd probably cause more than 150% damage to his opponent. More proof of Mario's superior strength- in Super Mario bros. 2 he is able to pull items off the ground more quickly than Luigi. Mario is also faster than Luigi. In two player mode, on the Great Fox level of SSB, I put Mario and Luigi at the tip of the Great Fox, with Mario in basically the same place as Luigi, with Mario a little ahead. I started them running at the same time and the gap between Mario and Luigi began to grow and grow. When I put Luigi in front of Mario, there was no gap at all. In fact, the only reason Luigi wasn't behind Mario is that it's impossible on SSM for a character to go through another charcter who's moving in the same direction as they are. Luigi isn't that bad though. In fact he's rather good. He can jump higher than Mario can, which makes up for his lack of speed, and he is also smarter, making up for his not being as strong as Mario. Therefore, the brothers are about equal, but I still like Mario better.
What'chu talkin' bout, Dextah?