Well if you're taking the honest anime approach, then I completely understand your argument. However, I have never seen the anime and... really don't want to tbh. I've never seen the Raichu as a heavyweight, due to statistics from the pokemon games in comparison to pikachu. He's faster and stronger, and I also recall that brawl cuts a lot of things out in terms of consistency. (Like Ike being slow, he isn't remotely slow AT ALL in Fire Emblem games)
My visual of what it was to be, based on the pokemon games, was that pikachu would host the more physical attacking because he already does in game, and that the Raichu would be more agile and elegant (somewhat like a kangaroo based on the feet thing) with faster attacks, somewhat less damage overall, but more perks like sweetspots and power increases.
This said, it doesn't mean I'm not going to take what you said into consideration. I'll look over your moveset again every once in a while and probably make changes to my own based off of it. I appreciate it

^^
You really should watch the episode when Ash's Pikachu fights Lt. Surge's Raichu. But it has to be the whole episode, the way things happen make the fight be epic.