The one in the last two photos is looking like a cockerel. The rest look to be pullets.
I would try integrating them as soon as you can. It's much better to bring in the new ones when they are still relatively young. Polish roosters generally aren't too aggressive, so hopefully yours won't be. Problems may crop up if the Cochin rooster tries to assert dominance over the Polish at some point. It's really a wait and see kind of thing. The pullets will also be bullied by the other hens, so you really have to keep an eye on things until they settle down.
If you have the space, you may prefer to keep them separate, and there's nothing wrong with that, either.