The attacks are good except for 3 things:
Charizard:
Blast Burn is very expensive. i recommend discard no energies.
Blastoise:
Hydrocannon is expensive. i think it should be {WWCC} and not {WWWCC}.
Venusaur:
No problem with attacks, 'cept that Venusaur is not pure Grass type. therefore, it does not have Water resistance.
FYI Blastoise+Venusaur are normally 110HP, and Charizard should have water weakness except for lightning. however, i know charizard is flying, but it is not the main type.