hello and welcome!
Do you already have the two week olds and four week olds together?
did you see the eight month old is a drake?
Are your two and four week old sexed?
You may still have problems even after they get used to each other and get along because you don’t want the older Drake to mate with any young females until they’re at least four months old
i’m thinking if they’re not sexed and you have a mixture of Drake‘s in your two and four week olds, you may be able to voice sex them when they’re maybe 5 to 6 weeks old which we could help you with and then put some Drakes in with your mature Drake, so he’s not lonely anymore but I wouldn’t let the older Drake mix in with the females until they’re four to five months old (five months is better)