16 weeks is not a bad age to eat the cockerels. That would be my plan just to keep it simple if you know which you want to keep. If you don't know which ones you want to keep then integrate them all.
Since they have been side by side for so long I'd open a gate between the two runs and let them mingle. If you are at home this weekend so you can kind of observe might be a good time. Part of what I'd expect to see is that the pullets will probably very quickly learn to not invade the adults' private space. If they do they could get pecked or worse. And at night I'd expect the pullets to sleep in their old coop, not join the adults in theirs. There can be exceptions to any of this, you never know for sure what will actually happen with living animals. Sometimes I see exceptions but this is what I'd typically see. Base your actions on what you see, not what some stranger like me over the internet tells you that you will see.
I don't know what will happen between those boys and the adult hens. There are many possibilities. One possibility is that the boys stay with the pullets and the hens aren't bothered at all, at least for now. The hens may beat the crap out of the boys because that's what some mature hens do. The boys may try to mate with the hens. Some hens might let them, some might run away from the boys, some may fight them. You never know. One thing not all that uncommon with a bunch of mature hens and one or more immature cockerels is that some hens let the cockerels mate them but the dominant hen knocks the cockerel off so he knows she is in charge. It can get violent and messy. It doesn't always but it can.
If you read some threads on here you'd expect those five boys to currently be tearing up those ten pullets since they are housed together. The feathers would be ripped off their backs and the back of the head, the pullets would be stressed out from being constantly mated or gang raped, maybe the pullets would not be eating because they are so intimidated by the boys that they are staying in the coop, maybe on the roost in the coop, to keep away. This kind of stuff can happen. It does happen, but maybe you aren't seeing it yet. I usually don't see it either, at least not very bad to where I see it as a problem. Usually does not mean always, sometimes you can have serious problems.
Again, I suggest you make your decisions based on what you see. Sometimes this can go really easily. Sometimes it can go really bad. I firmly believe the more room you have the better your odds are of it going easily. The less you force them to be together the better your chances, try to let them go at their pace. And have a place or way that you can separate one or more of the boys from the rest of the boys, pullets, and hens at a moment's notice. If the need comes up it often comes up pretty quickly.
Good luck and let us know how it goes, whatever you decide to do.
