"The original arcade game version used an unusual screen setup that situated one display in between projected images of two other displays, creating the appearance of a triple-wide screen" (from wikipedia)
People have certainly setup 3 monitor systems (which I'd guess it's the same as 1 monitor and 2 projections)
On mine, it plays pretty well on 1x21" horizontal monitor but would be less black space of course with 3 (or even 2 as a compromise). It makes it dedicated though and that's not the way I'm heading - it's playable on 1 screen for me.