If your ever going to get them into one cage it has to be a different cage.
The pecking order has already been set in the respective cages.
Yes they may never get along, but you can't judge by letting them in each others cages, or puttting them all in one of their already cages. Make sense
I am not sure you will be able too as they are all adults. Their seems to be better odds between adults & kits, or all kits starting out together. Adults can get set in their ways and just not want to bother even dealing with a pecking order, some want their own cage and that's it.
If you can get them all playing in a neutral area, bathing and taking treats from you while together , you may have a chance. You'll have to get a new set up, or completely clean , change around, and add to the exciting cage while they are out of it.