Incorporating my flock

Hello all.
My question is when is it a good idea to incorporate my old flock with my new flock.

Currently I have (3) 1yr old chicken 2 Easter egged americunas and 1 large amberlink roo. They been out side a while in their new home we built this past fall.
This past October/November we got 4 new chicken 1 silkier roo at 1 month old and 3 chicks 1day old( 1 Wyandotte 1 buff Orpington and 1 Rhode Island Red) As this point that makes them 4/5 months old. We just moved them out side in a smaller separate coop about a 1 n 1/2 months ago.

We have slowly been socializing them so that we can place them all together. Both coop are side by side allowing viewing of each other. But my silkie is scared of the other roo. It doesn't stop him from trying to assert his dominance but he then runs away screaming. It makes me nervous my silkie is so small.

My girls on the other hand are still unsure of their surroundings. My silkie can gather them together well. . But they still seems so unsure of themselves that the stay in the broader most of the time. We have on a few occasions had to force them out to move around more. When they are out they stay so close to my silkie.

Ok so when should I put them all together and should I put my silkie with everyone else. The purpose of the extra girls was to incorporate my silkie with my other Roos and chicks as a group and not alone but now I'm not so sure.