That's true. I had held thoughts of RC's tough season throughout but I had forgotten about your's.
The plan to bring in only vaccinated sex-linked pullet chicks should reduce the number of hard seasons. No doubt the occasional cockerels and diseases will sneak through every now and then.
Although it's an unpopular approach, hen hatching is ruled out because I can't vaccinate chicks or in ovum at home. (I hope it goes without saying that home or vet vaccinations have been discussed with several vets and I've gone into the procedure and cost thoroughly, both of which, of course, are different in other places.)