thanks we have mixed as well (BA6 GC5 BO4 EE3 GLW1) can't wait for eggs and to variety of colors lol.It is hard to tell. In the pen of 14 Black Sex links, 2 Production Reds, 1 Amberlink, a Silverlaced wyandotte and an EE, the EE is tge only one we are sure isn't.
In the truly mixed flock pen, the Barred Rocks lay huge eggs with the Leghorns running a close second. Both lay in the ex-large to jumbo on a regular basis.
6 EEs are just getting going so are still kind of small but regular now.