I dont know about damage output, but with water attacks, since you cant choose the attacker you will loose by type for the most popular pokemons now like:
Dragonite, Lapras, Golduck, Slowbro, Eggxecutor, Venasaur, Blastoise, Victribell, Vaporeon, poliwrath, vileplume, gyarados, etc.... so you are loosing for almost the stronger and most used pokemons... With rock atacks you have type advantage over dragonite, lapras and have normal damage over the water and grass types. The difference is huge right?
Omastar with water moves
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?
Omastar is listed as a good defender with the rock moves, how much would they be downgraded with water gun/hydro pump as a defender?