I don't know if this will help you or not ...
the way I've integrated in the past was to partition off a part of the coop and let them see each other but not touch. I could tell the big girls were ornery - they would pace in front of the partition. After a week, I started to let them have some supervised time together. That was gradually increased and then they had small blocks of unsupervised time. It took a long time (about 6 weeks) - but it did work. It was a pain in the butt, though.
This most recent time I integrated - I actually built a temporary run in my garage. It was 10Lx8Wx8H. It served as the brooding area and grow out area. (made from 1x2 boards with deer net for the fencing - it was in my garage so didn't need to be predator proof - just escape proof) Once they were about 12 weeks (they had feathered out and were no longer making baby peep sounds) - I took the big girls - one at at time - and put them in the 10x10 run with the little ones - one every other day - until they were all in the 10x10 in my garage (the baby house). The new surroundings seemed to throw them off and it worked very well. That took about 1.5 weeks - then I moved them all out to the big coop - and during the day - put the temporary 10x8 off the door of the regular run so they had more room and an escape area if need be. At night, they all got closed up in the same coop. After 3-4 days - I stopped pushing the temporary run up against the permanent run. When I was home - I'd let the big girls out to free range, and the youngsters had to stay in. Now, they all free range when I'm home. I still have two feeders though - as the big girls still don't want to give up control of that. But all is good - and there were no major issues. I integrated 5 silkies and 5 LF into my group of 6LF. The numbers probably worked in my favor as well, though.
The only problem I had was one silkie did take a bad peck(or two) to the head during the normal pecking order sorting - and she ended up with some neurological damage - I separated her for a while and tried various things, but she didn't improve. I'm not a silkie expert, but from what I've read - it's not uncommon for that to happen.
I think the best advise I'm going to offer, though, is patience and lots of supervision in the beginning since there is a problem with more serious aggression. Maybe remove the big girls from their surrounding for a week if possible - and put the silkies there - that may unsettle the big girls just enough to help reduce the aggression ... ??