have you tried fencing off a little area for the new chicks? i stapled some chicken wire to a corner of our main coop that included the perch, built a little door, and i stuff all new chicks in there, they get a protected spot on the roost and they get to know eachother, after a week or so i let them out.
I've found it works better introducing a large group of 10, and also splitting up a hatch, take all the bigger ones and intro them, meanwhile what has hatched before them is put in with the other half of the chicks and they get to know eachother, then i intro the other half of the first group the same way, but they only need to be locked up a few days as their buddies are already integrated, then after another week or so of them sorting everything out, i add the next group, leave them in for a week or so, then bring the other half of their hatch in and only leave em for a few days.... idk but the coop has been much quieter, they are so used to new chicks moving in that they dont attack them, pick a little, but NOTHING like last year where we would hear screaming coming from there...
so in short i guess split your group up if its large and then they will have buddies... but if its only a few just giving them a little piece of territory where the bigger birds can safely interact with them without being able to peck them..
for my ameraucauna group its always easier, i just throw the group in and within a few days they are fine, the hens will play "I'm the giant" with them and stomp around and growl and they run screaming, but very little pecking and when they do its more motherly and chiding then aggression, the babies will bunch up in the corner and a hen will go over and break em up and scatter em, it looks like they are doing it just to be evil lol, but not really mean... the bantams though, they do make integration more difficult, the hens tend to be bottom of the pole, so they are the ones that give them a hard time, and more roosters, fine together, but add in a new bird and they go right after em, i have to play ref for those intros....