Gym Tier lists.

While waiting for the list from gamepress, I am trying to identify which Pokemon should be considered for gym battles.

Can you please give me your feedback on the following lists?

Gym attackers tier list

Tier 1: Great attacker against a wide range of defender
Machamp, Dragonite, Tyranitar

Tier 1.5: Best attacker against at least one (defender)
Jolteon (Gyarados), Flareon (Steelix), Charizard (Exeggcutor), Vaporeon (Rhydon), Heracross (Rhydon), Gengar (Exeggcutor)

Tier 2 : Second choice attacker against at least one (defender)
Piloswine (Dragonite), Exeggcutor (Vaporeon), Venusaur (Vaporeon, Lapras), Lapras (Rhydon), Gyarados (Rhydon), Golem (Charizard)

Tier 3 : Third choice attacker against several defenders
Snorlax, Donphan, Ursaring

Gym defenders tier list

Tier 1
Blissey

Tier 2
Snorlax, Chansey

Tier 3
Steelix, Lapras, Umbreon, Vaporeon, Rhydon, Tyranitar, Dragonite

Tier 3.5
Militank, Muk, Donphan, Gyarados, Slowbro, Slowking, Golem, Poliwrath, Omastar