putting 7 week chicks and 4 week chicks together

[mener6896]

I hatched 2 chicks that are now 7 weeks (both roos) I then hatched 10 chicks that are now 4 weeks old. Is it okay to put them together now? the 4 weekers are a little too old to stay in my sunroom. I'm a little concerned about the older roos picking on the little ones, but hoped since the little ones out numbered them it might be okay.

Advice?

 

[sumatra]

Is there a big size difference? And what breed do you have?