You may not be too late, I figure 1 1/2 - 2 more brood cycles, Sept to Oct. I have 2 hives in the process also, but they have lots of Summer bees to help (hopefully) I help them along as much as I can.When I did my last batch all but one got balled. I didn't realize it until I was placing the last one and I could hear her "screaming". I dug her out of the hive and got the ball away from her. She promptly flew off into some brush. The only one that didn't get balled is still in the cage. I want to get her out but don't want to lose my last queen I produced for the year.
She's been in there for 4 days now and the new nuc is still all over the cage and I can't shake them off. I believe that's a sign they don't want her. She should have gone on flights Fri/Sat but is still caged. I'm not sure how to do this one.
The other nucs are all making a queen. I assume they will be too late but I'm going to let them go and later do some combines if it looks like a lost cause. Winter is coming.
As for introducing I usually don’t have a problem for whatever reason...If they are all over the cage maybe they want her really bad! The time I did have a problem there was a virgin in there. If you can get dome of the attendants out that may help also, I think the hive bees might be wanting to sting/kill them not queen, she gets in the way.