Depends on how much rocks you have. If it's wide open with not much rock, it may be ok. Otherwise, there would be some dead spots.
My tank has 2 Koralia Mag 8s, 2 VorTech MP40s, 1 MP10, and 3 other older Koralia. Only the VorTechs are always on. The Koralias are controlled by an AquaController Apex System to provide surge current on different area.