Isn't it obvious that there aren't much any decent fan controllers at low budget.
Aquacomputer Quadro is way best in configurability.
https://www.overclockers.co.uk/aqua-computer-quadro-pwm-fan-controller-wc-338-aq.html
Anyway there's no sense to have intake fans connected separately.
And that case leaks out every slightest noise unmuffled.
So avoiding unnecessary fans is very important for minimizing noise and trying that "positive pressure" with more intake fans than exhausts while opening slots for airflow would be worth of shot.
Fans with good pressure characteristics should be able to force airflow through case without needing high RPM.
While that NF-S12 is no doubt one of the worst fans to put into any cooler.
Arctic P12s would certainly beat those while costing one third.
Wouldn't use those in much nothing else than in open holes without any grills/meshes.
P-Q curve has nothing to do with RPM variation.
It's all about fixed speed fan's ability to do work at various loads.
And actually general shape of curve doesn't vary that much between most speeds.
Airflow/pressure values corresponding to each part of curve just vary:
http://www.scythe-eu.com/en/products/fans/gentle-typhoon-120-mm.html
https://catalog.pelonistechnologies.com/Asset/p1238-7pcurve.jpg
