All radiators as exhaust? I don't really see how that wouldn't just create a dusty mess inside the computer. That means it would be pulling air in from every crack and crevice.
I would probably just leave out the 120mm radiator for simplicity. I have a 12700KF and a 3080Ti with two 280mm radiators, that is plenty. Front radiator is intake, top mounted radiator is exhaust. Rear fan is intake.
Just remember that the air temperature isn't likely to exceed the temperature of any heat generating component inside the chassis. So even the 'warm' air can still cool things. The key to keep that air moving and get it out of the system at some point.