i simply swap locations with a strong hive... the foragers will go into this hive just fine and add strength to it.
commercial guys call this "equalizing"...
that is a hazard job. It is very different what commercial guys do and what does first year beekeeper.
At least you destroy a good foraging hive. Second thing is that you may get rid off one or both queens.
when you give a frame of emerging brood, that is simple and effective trick. Shake all bees off that they do not kill the queen.
If you give 2 frames to a weak colony, probably it is not able to keep all brood alive and part of brood will die. You may give a second frame after a week.
But it is well done if your are first year beek and 6 hives. You will be in a hurry next year.