Guardianship Traits

What is the link between guardianship and separation anxiety? Lots of questions (and helpful answers) on these pages!
The guardian genetics of the Pyrenees is generally thought to be its strongest character trait. It's also safe to say that the degree of guardianship tendencies may vary with individuals of this breed.
This site has been a lifeline for 2 experienced dog people with their first Pyr, I can tell you, as we quickly realised that our new dog is unique in every way by comparison to every other canine that lived their life with us.
A 'real busybody', we call him. He lives with 2 retired humans, an older dog and a cat (who thinks he's a dog). Separation anxiety has not been an issue with him. So, why is this so? And why is it so extreme in some other Pyrs, that they engage in destructive coping behaviour when left alone at home?
Perhaps the key to that is: a)guardian genetics as opposed to learned (trained) guarding
b)inability to cope with separation from their 'flock' that is stronger in some individuals than others and,
c) genetic programming that will not allow these dogs to over-ride the need to be with their flock at all hours, in all conditions and circumstances.
So, 'learned guarding' can be refined, added to, and specific coping skills taught, right?
Is this even possible with a Pyrenees, whose guardianship is inborn? Whose 'flock' could be comprised of individuals in a home or, stock in a field? And, whose other best character trait is having their own mind about all things?
Weigh in, readers! I'd like to know!