Ehh. I dunno man. Here is what I think. Only counting "Official" Battles (League, Gyms, Frontier, Whirl Cup) and counting all of their forms combined...
Infernape is top tier with 10 wins, 2 losses. That's easily the best Pokemon he has with it's incredibly high W/L ratio and the fact that...It's pretty fucking strong! Tier of his own, easily.
Krokodile has a decent W/L at 3/1. Bump him up a tier.
Snorlax 8/3...yea pretty good spot for the fatbro.
Sceptile 8/10, drop him at least 2 tiers, dude is kind of a loser.
Corphish and Charizard both sitting at 11/6, but obviously Charizard is a whole lot stronger. Id leave the 'Zard where he is and bump Corphish up a notch.
Torkoal is 2/6, Lapras is 0/0, and Muk is 1/1, all pretty garbage tier. Pidgeot lost his only official battle and that's if you count his "win" against Starmie (I do).
Worth noting that Kingler is 5/2. Squirtle is kind of a jobber and incompetent while Brobasaur is 5/2 also having 2 fights ending in a draw.