These are DWARF monitors that only get about 2 feet in length. They are not your average Savannah or Nile Monitor. 4x2x2 is enough room to house 1 male and 3 nesting females, but I cut it down to 1.2 because I had the space and its easier to feed them.
They ARE social eaters in that for the bigger prey (like the mouse in question), several of them will take it down and make sure its dead and of no harm. Put a smaller pinky or maybe even a mouse "part", and they all eat individually. Watch Komodos on Animal Planet or Discovery. You'll see social eating. Monitors aren't built like other lizards.
Here's a pic of the outside of 2 stacks of cages in the old monitor room:
