I have 2 weak hives: one because it swarmed, the other because of a failing queen. I'm planning to pinch the subpar queen and do a newspaper combine. But...
I also have an observation hive, which I populated with stragglers from the swarm, adding a new queen. The O-hive population is very low: not even half a frame.
Could I go ahead and combine the 2 weak hives, but set aside a frame of brood and put it in the observation hive? If it worked, that would leave the population of all hives about right.
You could do that. Pinch extra queens and then combine the next day, so all the bees get the message that the queen is gone. If these are small hives, you don't have to do the newspaper bit. Just put the hives together. The more confusion the better. Combining with lots of smoke or a mist of vanilla extract spray will help. Combining more than two hives at once also helps the confusion.