I can’t recall the amp draw. I’m running two 12in fans. Each one can pull up to 1550cfm. They’re controlled by the same set point. Both on and off at the same time
That should be enough CFM to feel them pulling air a few feet in front of the radiator, no? Try lowering the temperature they start at. There are several companies that make staggered and soft-start harnesses to reduce the amperage draw on start up.