I was having a rough time integrating my younger in as well. The first night was rough, the littles cried hard, they're on day 3 and slowly coming around. I did a look but don't touch approach for a few weeks before integration because when I attempted to integrate the other way they were just going after the littles way too much. Because my littles were a lot smaller I was worried about injuries (they pecked the crap out of the littles, drew some blood). After building the mini coop and doing the look but don't touch it's gone a lot smoother. I hated hearing the littles cry so much, but I did NOT want to back off, I needed to just make that leap (they're big enough now that I'm not as worried about them getting hurt, and they have ZERO desire to fight back, they just want to be left alone). Today they were ALMOST brave enough to come all the way out of the coop into the exercise pen, not quite, but it's progress.