Eh...well there are somethings you have to take in account for. Hydro Pump is an attacking move instead of supporting, but it's a special move not a physical. If you want Hydro Pump to do the max damage it can you have to have decent stats in Sp.Atk. Now if you want a move like Skull Bash which is a physical move to do heavy damage than you raise it's Atk stat. It depends on the nature of your pokemon and what moves you want for it.