I expect that gliders will sometimes just wrestle for fun like my dogs do -
Have you ever watched two dogs 'play fight'? They can sound pretty vicious but no one is getting hurt. Mine even choose a soft spot to hold there 'fights' either on the couch, the middle of my bed or on the throw rug in my family room rather than on the hard tile.
Your gliders may need some additional toys or distractions to focus their attention on something other than their cagemate.
First - if you think food may be involved be sure to put their dinner in several locations in the cage - some high some low so they have to do a little foraging for dinner. Hanging bird cups work well and can be moved around to different places each night.
Add some toys to the cage. My gliders like to have small places to hide - where they can pop out to surprise other gliders or as a place to sit by them selves to munch on a piece of food. Toddler shape sorters are popular with my gliders. A particular favorite is an inexpensive castle from Big Lots that has a draw bridge for a large door but lots of shape 'windows' to peek out of. There are also some to be found in the small pets section of most pet stores - the Cake and Strawberry make great hide outs.
I also put small toys like plastic bracelets, monkeys (barrel of monkeys game or similar ones available at Dollar Stores) straws or even plastic army men on top of the cage for the gliders to grab and pull through over night. I get to have fun picking them up from the floor and bottom of the cage each morning - so I toss them back on top of the cage for another night's fun.