I think they are young enough that they should adapt to each other fairly easily, but I would wait until the youngest are 6 weeks. That way they're all about the same size. Since your 5 week olds are already in the new run, you will probably want to put the younger ones in the run inside a smaller pen of some kind, so they can see and be seen, but not touch. After a few days of that, you should be able to let them loose together. Keep a close eye on them, though, because every bird has a different personality, and some may get along fine while others don't.
It sounds like you have plenty of space. If there are plenty of places to hide as well, the integration will go even smoother.
