Hey Guyswithchicks, do you have an update yet? I'm looking forwards to your outcome.
Regarding "to cull or not to cull", I have a bit of a story. I did not believe early on in culling. My birds free-range except when the hawks or coyotes are active. They live a pretty good life. A few years ago, I had two beautiful grown roosters. One was blonde, and the other white. They were both knock-outs. They were hatch mates. I heard a commotion one day and thought a hawk was in the chickens. I looked out to see the two young roosters fighting one another, for the first time ever. They had chased each other before, but to my knowledge they had never fought before. I ran back inside to get my shoes and ran back to where they were fighting. It did not take me but about 90 seconds to get back outside. I couldn't find either one of them at first. Then, I found the blonde one on his side, bloody and panting. A few yards away, I found the white one, also bloody but not breathing. It was July. They both died. My assumption was that they had chased each other before fighting, and they died of heat stroke. I wouldn't have heard them simply running. I lost two beautiful roosters to their own nature, without them ever being confined with each other or in any way encouraged to fight. They just got that age, and bam! I had about 35 hens at the time, so it wasn't due to a lack of hens.
So, now, I keep one adult rooster, and when he gets to about four years old, I let a younger one become an adult. The others become dog food when their age becomes apparent. I only hatch every couple of years to replace whatever has been lost to age, hawks, and the other myriad of things that love to get chickens. I decided it was better to cull the roosters before they become too old to serve another purpose than to lose them because their chromosomes tell them to fight one another to their death.
I also have ducks. I finally culled two of the drakes a few weeks ago, and it has changed the peacefulness of the whole flock. The girls see more peace now, and the whole flock is quieter, rests more often, and just generally seems happier. They also free range.
I'm not sure I don't see it more like pruning my raspberry vines or the pear tree now - If you want fruit, sometimes you have to trim back the branches.