Sorry, I did mean horizontal.
At three foot, you have a circumference of 18foot. The idea of almost 180° of monitors still unsettles me. That's beyond neck work, that's practically into separate workspaces. If you're looking at the left side of Monitor 1, Monitor 3 is physically out of —even peripheral— eyeline.
I don't know why I'm flapping on about it. If it works for you, that's great.
you are right that 3 monitors is excessive. I find myself only really using 2 of them.
Using the 3rd requires me to twist my upper body a bit uncomfortably. as a result I find that I tend to keep it dedicated to little used apps, like email and sourcetree (a git gui)
it's only about 2' of vertical space, but 8' of horizontal, so I have them laid out in a semi-circle.
I have 39" seiki TV's, all about 4 years old now. As one of the other posters mentioned, it actually seems rare to find any 4K TV that small any more. But a brief search on amazon shows you can still get stuff in that price range, but Seiki seems to be gone :(