Hey everyone, first post. Might be doing this wrong, crucify if you must lol But would love some advice and let me know if I’m doing something wrong anything I can be doing to make things easier. Much appreciated 
My original flock are 8 - 4 week old chicks
2 barred rocks
2 australorps
1 Easter egger
1 maran (?) not sure if blue or black or cuckoo
1 golden laced polish
1 welsummer
Adding 15 - 1 week old chicks
3-Rhode island reds
3-Easter eggers
3-buff orp
1-Lav orp
2-French black copper marans
2-olive eggers
1-surprise chick - looks like a cream legbar imo
So for the first two days after arrival of the new baby chicks they were in a separate brooder. Giving them electrolytes and probiotic since they were sent in the mail and wanted to monitor for possible respiratory issues/bowl issues (cocci) All seems fine so I decide to integrate slowly.
I then added them to same brooder with a screen in between on day 3. All have separate heat, food, water. Everyone is thriving!!!
Day 5 I decided to let them mingle together with very low hopes it would work out. However it went pretty well. By end of day I separated again with hardware cloth to be safe!
Day 6 all day together but isolated the bully’s (only 2) once nightfall came I brought all back together, all went to sleep happily no issues.
Today Day 7 everything was good all morning by mid day we had some pecking, some that was more aggressive than I felt comfortable with. There are 3 from the older group (4 week) that are not being nice. I isolated with hardware cloth in same brooder. About 6 hours later I brought them back in and still they are nasty. I can tell those 3 were at the bottom of pecking order that had started within that group.
No blood drawn, no injuries..
My plan is to go about the day and let them go to sleep and see how it goes. Is that a bad idea? Hoping to get some input from those more experienced.
Thanks!!

My original flock are 8 - 4 week old chicks
2 barred rocks
2 australorps
1 Easter egger
1 maran (?) not sure if blue or black or cuckoo
1 golden laced polish
1 welsummer
Adding 15 - 1 week old chicks
3-Rhode island reds
3-Easter eggers
3-buff orp
1-Lav orp
2-French black copper marans
2-olive eggers
1-surprise chick - looks like a cream legbar imo
So for the first two days after arrival of the new baby chicks they were in a separate brooder. Giving them electrolytes and probiotic since they were sent in the mail and wanted to monitor for possible respiratory issues/bowl issues (cocci) All seems fine so I decide to integrate slowly.
I then added them to same brooder with a screen in between on day 3. All have separate heat, food, water. Everyone is thriving!!!
Day 5 I decided to let them mingle together with very low hopes it would work out. However it went pretty well. By end of day I separated again with hardware cloth to be safe!
Day 6 all day together but isolated the bully’s (only 2) once nightfall came I brought all back together, all went to sleep happily no issues.
Today Day 7 everything was good all morning by mid day we had some pecking, some that was more aggressive than I felt comfortable with. There are 3 from the older group (4 week) that are not being nice. I isolated with hardware cloth in same brooder. About 6 hours later I brought them back in and still they are nasty. I can tell those 3 were at the bottom of pecking order that had started within that group.
No blood drawn, no injuries..
My plan is to go about the day and let them go to sleep and see how it goes. Is that a bad idea? Hoping to get some input from those more experienced.
Thanks!!