need help putting a team together

I'm writing a fanfic with 2 characters who are rivals, and I want the rival's team to be a good counter to the main character's team, but still having a possibility of losing to the main character's team. Problem is, I suck at team building. Which Pokémon would you say work well as a counter to the following team? Please note, the fanfic is supposed to take place in gen 1 and the rival must have Blastoise and an eeveelution.

Chari/ Charizard
-Flamethrower
-Fire blast
-seismic toss
-Dragon rage

Poli/ Poliwrath
-hydro pump
-hypnosis
-strength
-surf

Pika/ Pikachu
-thunder
-quick attack
-thunder wave
-swift

Snor/ Snorlax
-Hyper beam
-body slam
-rest
-earthquake

Aero/ Aerodactyl
-wing attack
-hyper beam
-fly
-rage

Jewel/ Ninetales
-flamethrower
-confuse ray
-fire blast
-Toxic

for the few people who have read the first 4 chapters of the fanfic I'm talking about, please don't say anything about it.