We played a fun 3 way Apocalypse game Saturday, which was wild enough but perhaps not set up ideally. Just throwing up a few thoughts in case we wanted to do something similar again. We used two tables and the table partition in green below.
Cookie chose a very slow deployment time, and was left with the deployment zone in the middle. The two guard players wanted to shoot, and deployed back towards the short table edges. Cookie got caught in the middle, engaging and getting hit by both guard armies. The two guard armies were far enough apart that very few units had the range to engage the other guard force. As the male guard dominated in terms of long range weaponry, after the marines got schrod it was the lady's turn.
I'm thinking that next time around we might try something like the purple partition. The armies with the long table edges to their rear couldn't back as far away from each other. There is more direct contact should the two forces want to close. The two outside armies wouldn't be quite so obviously be pushed to clobber the guy in the middle before engaging each other.
Not that I am particularly advocating 3 way fights. They are a nice fun change of pace. Still, if anyone else wants to try it, they might consider the purple partition approach.