BrandonNealeyAs long as you don't want to angle the side panels in very far, you should be alright. I can't imagine a 28 and 2 x 23 would be wider than 3 x 27. However, the extra size on the middle monitor might prevent the side wings from pivoting on as much as they normally would.
BrandonNealeyI just measured mine and with the angle I have my outside monitors at the center monitor could be 31 inches wide and be barely touching arms. However at that width I measured that the side monitors could only measure about 8.5 inches from their center to the side touching the center monitor. I don't have the arms extended all the way, but I don't think they could go much further (probably about an inch). I think you should be fine. I do have mine tilted pretty far inward though.
If you want me to take other measurements I will (as long as I don't have to move my monitors to do it).
BrandonNealeyHi Brandon,
You should be able to do that. The main concern is I would have is the weight of the 28" monitor. As long as it is under 25 lbs you should have no problem with your proposed setup.