You might run 4 of them, and turn them down, for better coverage, especially with Acros.
A single AI prime has a recommended spread of about 18x18". But more may be needed for sticks.
Acropora is just a different animal. You'll have to see how they do. I think you'll have shadowing.
I would run them all if you still have them. It will help with spread and shading.
It looks like a 4' fluval 2.0 is about 59 watts at full power on all channels. I haven't taken a PAR meter to one, but I would guess it's pretty similar to a single T5 bulb.