I think you are doing it wrong! (not trying to be mean.)
www.sugarglider.com/gliderpedia/index.asp?Introductions
IMO....You are going to fast. Gizmo seems to be protecting his territory.
1. cages away from each cage. ONLY swap sleeping pouches.
I like 2 sleeping pouches in each cage, after each glider smells up his pouch,
maybe 4 days, switch the pouch they have been sleeping in. After 2-3 days switch
the pouch they are sleeping in again, repeat every 2-3 days. I look to see
which pouch they are sleeping in, If they don't except the foreign scented pouch
after a 2 weeks, not sleeping in it, they remove the 2nd pouch and force them to
sleep in the one pouch.
do this a minimum of 3 weeks, you want them to get used to the new scent("glider) and except it as part of their world.
2. put cages 8 inches apart, let them be together that way for a few weeks or more. going longer time is better then shorter time IF needed.
3. for us, they usually have a smell moment, maybe a short quick spat, usually
when one gets on the other to tell them they are in charge. if they BALL UP and fight we move them apart or stop the introduction (PS. introduction in UNscented
place, we use bathtub) After 5 or 10 minutes in tub with NO fight we give them an
UNscented pouch to get into. they go into it (this is most scary for me, as if they start a fight in pouch, harder to separate) and they start hanging out in pouch
together... don't think we have had a fight in the pouch, if they are willing to
go in pouch together they are in a good place.
we only have neutered males. so don't know if unaltered males would be harder or not.
good luck