I'd recommend one video card that has all the outputs you need.
Adobe wrote Different GPU conflecting drivers two GPU that are the same I believe should work. Not positive
Multiple graphics cards with conflicting drivers can cause problems with GPU-accelerated or enabled features in Photoshop. For best results, connect two (or more) monitors into one graphics card.
The Nvidia Quadro 4000 in my machine can drive two displays max size 2160x1600 it drives two 1K displays
The Nvidia Quadro K2200 on my wife's machine can drive three Displaye 3868x2160 drives 2 1600x1200 displays and one 3860x2160
The Nvidia Quadro M2000 in my sone machine can drive 4 3860x2160 displar is onle driving a 1280x900 display
I would sneak is his room at night but he is up gammins all knght. He would notice the swap anyway the M2000 handles gamming much better than my 4000.. the K2200 also does..
Smome thing a quadro can't handle gamming I saw a video where some nut hooked 16 4K displays with 4 Qyadro P5000 and was able to actually to play some games 15,360px x 8,640 around 124MP
Now that is some set up .
I am looking at a Quadro P2000 to replace my AMD HD7970 3GB. The AMD card has 6 ports and the Quadro has 4 but in reality, I only use 3. The main reason for changing is that Blender has dropped support for the older AMD card in it's latest version, so I now have no GPU acceleration for 3D in Blender.