To add to my earlier thoughts. It seems that most people seek out friendly, calm, docile breeds. Things like orpingtons, silkies, brahmas, cochins, etc.. I have no desire to hold, pet, hug or kiss livestock. I only handle them out of necessity for evaluation. After over 30 breeds of chickens, I can say that people who want egg laying machines and birds that do their job while being fairly predator proof are doing themselves a disservice by avoiding the skittish (flighty) breeds.
I wouldn't own polish again nor would I consider a silkie. I have too many around-the-clock predators to have breeds that aren't self sufficient.
On 2 occasions I've seen a fox grab an Orpington in the middle of the day before the hen knew anything was afoot. I've seen hawks pick up docile breeds and birds with obscured vision.
I can assure that none of those things would happen to a Penedesenca or similar wary, fleet footed breed.