Since I posted photo above I have had 18 hatch. In the past I’ve only hated one or two at a time. When I put the babies out (about 6 weeks old) the oldie Guineas (less than a year old) really attacked and tormented them. (I introduced 3). They are now separated from the rest of the flock. The 3 won’t come out of the coop. Is there a better way to do this?
I'm sure you will get different responses to your question, but I'll share what I have experienced. I do not have good luck adding new members to an existing flock; others have had better luck, given time. Any new additions are NOT welcomed by my existing flock and I don't just dump them in together. I start with hearing, not seeing; seeing not interacting, then full interaction after at least a month.
I have large flocks that are keets together and they really bond. They create one social unit and do NOT welcome others in. I tried to add 4 to an existing flock of 12, they free ranged together, but the existing flock tormented them, even though most were female and the flock was low in females. This year, I've had two large flocks of keets, a month apart and again, they free range together, but do not roost together or really mix. Occasionally, I'll have a female leave the older (dominant flock) and join in with the younger (less dominant flock).
In general, and to start with, I would say your older Guineas will be the dominant flock. If you can wait until the younger ones are about the same size, that would help. I'd say until 12 weeks. Then if you can have them see each other, but not interact for a month, that would help as well. I'd introduce ALL of the young ones to the old ones, because any new addition is going to be low in the pecking order and there will be safety in numbers.
Mine continue to air peck and chase each other, but there's no blood drawn. That's when I intervene. In general they are more aggressive with each other than the rest of the poultry here, but many will tell you they rule chickens, not here - my Rhode Island Reds keep the guineas in line.
Please keep asking questions here. You many get a variety of answers based on our experiences, but then you can pick and chose what will work best for you. Sometimes it's more of a matter of matching an idea with your situation and philosophy than being absolutely right or wrong. There are times when it gets down to what's right or wrong for the birds, but other times when you can be more flexible.
Good luck! Maybe others with a better track record of flock integration will post and give you more ideas. One thing's for sure, it takes time....

