[SOLVED] Can I put a 120mm RGB case fan (eg corsair LL120) onto a Cooler Master 212 Hyper?

Sep 15, 2020
Been lurking for a while, first time poster, sorry if this is kinda word salad.

I got this computer built by a retailer, and chose a cooler master hyper 212 black as my CPU cooler. When I was upgrading the CPU and mobo I realised that the CM allows for an 'optional fan', a second one on the opposite side to further reduce temperatures a bit. I'm also looking at upgrading the lighting in my case by swapping out some fans with corsair RGB fans, and was wondering if I could kill two birds with one stone; take the fan that's at the front of the CM, which I believe is a silencio FP120, put that as the back fan, and have another Corsair fan like the LL120 as the front fan where the silencio currently is. That way I have some lighting on the more visible fan and everything colour-wise is controlled through iCue.

I'm not going to be using a Corsair Commander Pro, just the lighting fan hub, and I currently run all four of my case fans through a splitter which has a fifth one free. My motherboard (Asus ROG X570-F Gaming) has both CPU_Fan and CPU_Fan_Opt pin sets, both 4-pin, and the RGB in the LL120 is powered by a separate thing which connects to corsair's own hub.

So there's gotta be some enormous gaping hole in this plan I'm overlooking, right?

Something in the way the fans are built? Pins? Maybe it would work as the 'back' fan but not the 'front' one? Just doing a double-check before I commit to anything here.