Fan Placement?

I have seen some articles compare whether fans should push or pull air, but is there any increase in performance if there is a fan in front pushing and a fan in back pulling? So you would have 4 fans on a dual radiator, thanks for your help!

2 fans pulling through (on a dual rad for example) is really all you need, if you're trying to squeeze out a few (1-2) degrees, then its worth it