I second the shake out. The bees will go into a hive in a humble fashion and there will be no fighting.
I combined multiple hives starting in August. The first three combines I lost all three queens. I have not had that much bad luck in many years.. All three combines were from pinching the queens and waiting three or four hours, then doing a newspaper combine with the newly queenless hive on top...
Three more combines were done, but a bit more carefully.. queenless overnight to start. A few frames of brood and bees on top of a newspaper combine, with the rest of the bees shaken out in front of the hive..
I in fact did this exact thing for the bees in my OB hive... My wife was not all that impressed with 20 THOUSAND bees flying all about the front of hour house.. the other ten thousand were in the top part of the hive.. By nightfall the shaken out bees had gone into the hive. Some in the top entrance where their original hive mates were, and MANY in the lower entrance accepted by the current occupants when they begged sheepishly at the door as it began to get cold...
I believe that their scent being accepted below helped the rest be accepted as they began to come through the paper. Using the partial combine and shake out after a minimum of 12 hours has worked flawlessly (so far) but give me and the bees some time. I am sure I can figure out a variation that wont work!