Bees should bee packed in , no use in them spending energy that they don't have warming up a hive that is to big for them.
It is better if the have a smaller hive,
If you have a stronger hive you can move a frame of bees that are about to hatch , with the worker bees still on it , to do this you hare to make sure the queen is not on this frame , to the weaker hive.
You can also place the week hive on top of a strong hive with a mesh mosquito net between the hives so the bees and queens cant mix , the week hive will benefit from the warmth of the larger hive , then they don't need to use as much time and energy keeping there hive warm.
mvh edward :-P