Hens go broody and if left alone, flocks are self-sustaining and self-populating. Predators have a hard time with this one as they are fast, willing to use their talons, and roost high up in trees.
Your TMA line looks very nice. The hen is bigger than the TMA hens I have seen though. Body shape is similar to GFF's new 2016 line. That's great! The Roosters comb is interesting is not standard like TMA, it almost looks like a toned down Bekisar comb. How does his crow sound? Is it a cry as...
usually about the time they start to come into their own, they will be ready to cull. They will start to compete and that's a good sign to thin them out.