After numerous tests, I have concluded that you can indeed fuse two Camponotus chromaiodes colonies of similar size. What I did was chilled one colony, and introduced one worker to each colony. If they feed the foreign worker after some time, they should get along. Then add one more worker. If the same happens, you are in the green. Then, attach both colonies nests together via an outworld. Let them find each other. Now this part can take time. If there is aggression, chill them for a bit more. If they find each other and feed each other, the move will be under way shortly.
NOTE: This is based off of my colonies results. Yours may not be the same.
Edit: I have had most success with fusing a queenless colony to a colony with a queen, as well as two small colonies with queens.
Edited by Ant_Dude2908, December 31 2018 - 3:44 PM.