Question about UNI FAN SL-INF 120 - 647710

I currently have 4 Lian Li controllers in the system at the same time.

Therefore you can use more than one, often an internal USB splitter such as [Akasa Internal USB 2.0 Hub Card (30 cm)
Akasa Internal USB 2.0 Hub Card (30 cm)
Shouldn't be a problem with 2 unless you have another internal USB port that you want to use...

However, mine does not recognise the fans and controllers correctly for the update (probably due to the 4 controllers), so I recommend doing this manually.
You can find all the information here:
lian-li.com/l-connect3/l3_update_manually/

So I only have the sl inf fans, but from the pictures I've seen, you need to use both controllers if you want to use the fans from the aio. If you use inf you can use everything from the controller that came with the fans. So that's what I've seen so far on pictures of the aio.
In my opinion, the controller of the aio is only necessary with the fans of the aio. I hope I was able to answer your questions halfway. Have a nice evening.