I once did a party of Zubat, Caterpie, Weedle, Magikarp, Paras and Psyduck on Pokemon, that sucked really hard. In the end the party ended up pretty awesome though because I had Goldbat, Butterfree, Beedrill, Gyarados, Parasect and Golduck in my party and well, when running around with that, not even the psychic gym is a problem because you just use Beedrill's bug type moves to wipe the floor with the lil' cow.