I found that Breloom, Tropius, or Bulba/Ivy/Venasaur can be used as a slave for FLASH, CUT, STRENGTH, and ROCK SMASH. Then just keep a water Pokemon that can use DIVE, SURF, and WATERFALL and then teach them a move from a different type so they can still be useful in a battle. The same goes with FLY, but I recommend Honchkrow or Sigilyph or another Pokemon that is more than just flying type. Honchkrow is great because he can learn psychic as a dark Pokemon.