I agree with beta, tank size will be key. Unless you've got a 6' tank, I wouldn't try all three types. With 55g or larger two types would work, just introduce the new one(s) on the opposite end of the tank as the existing one(s) hiding hole.
Since Firefish don't stray far from their hiding spot, and immediately bolt into a hole, upon introduction, you can almost choose where they will reside by where you introduce them to the tank.
I had 2 regulars in tank, got a great deal on 2 purples, and when introduced in the opposite corner, immediately picked a spot on that side of the tank. Tank was a 5', 135g. They did fine, living on their respective sides of the tank. Normally Firefish won't stray more than 2' from their hideout.