We have all resisted something, or the truth, because we want it to be some other way. Many always will, depending on emotion or fanciful ideas instead of experience and logic. They will continue to not like what is said (or wrote). It would be interesting if we could all look back at what we write in these posts five years from now.
What you are doing is learning and evolving. Something that we all do, and will continue to. There are many fanciful myths running about on the net, but those that stick with this on any serious level will come to a more sober place.
It is interesting to get the impression that you are serious about trying to do something. That is refreshing. Many just like the idea of it, and that is ok.
You can still devote yourself to one breed. Particularly if you want to include breeding for utility. The number one reason that we do not have quality standard bred lines of productive birds, is the qty that we raise. It requires numbers to prove pullets, and cockerels. Any intelligent effort requires proof. Then to remain faithful to the breed, we have to stay faithful to it's type. Variety matters, and utility lines should probably be simple color varieties. The more points of selection, the more time it takes to make progress.
If you have the space to breed two, what could you do with one? I am not saying to do this. You mentioned it, so I am saying that you still can.
Broodiness is both useful, and an additional management challenge. It depends on who is raising them, how, and why. Broody hens dictate when, and where. They decide. We do not. That can be a problem. It might be advisable to preserve the trait in some lines, and discourage it in others.
Good luck with your efforts. I hope that you do well.