Well... 2/4 pokemon are weak to fire, and 2/4 pokemon are weak to water. You have two key resists for those so I guess that's okay. Don't listen to Chikorita, Slowbro and Slowking are equal (though you can get Slowking much easier..) If you want a full rate, we need movesets too.
If I wanted to be really critical: You might want another Ice pokemon so you are less weak to water... Sneasel maybe? Failing that, make Lapras your Water/Ice type, and replace Slowbro with a physical attacker. I'd reccomend: Hitmontop, Electrabuzz, or Dragonite
Oh, and your HM slave combo leaves one move short: Strength. I'd actually recommend Red Gyarados with the following moves: Strength, Rock Smash, Waterfall, Whirlpool. Slowbro wants Surf anyway. For Cut, use Oddish early game, then catch Farfetch'd for Cut and Fly action after you get 4 badges.
Hope I helped.