You'll regret that decision as soon as you hook it up.
All monitors have slight differences, even newer versions of existing models.
Personally I game at 6040x1080 - 3 screens. I started out with 1 monitor (as most do) and added 2 more of the same screen that I already had...
Problem was, there was a small update and the original screen I had was no longer being produced and the model added one letter - that's how similar the 2 were.
Hooked them up, and the 1 was just a bit more red (not noticible otherwise) than the other 2.
If you have 3 different monitors, you will have 3 different appearances. And the only way to avoid that is to have 3 of the EXACT SAME monitors.
I had to go out and buy a 4th to replace my original so it would look good.
You do not want to mix/match your screens.
Will it work? yes. Would anyone recommend that who knows what they're talking about? no.