Are Shars LGDs on steroids because of mastiff blood? Most certainly not, they've been like that for a long time.[/QUOTE]
How confident are you of that really? Honest question, you may have good reasons to be very certain. I don't, at the moment.
Generally speaking, corpulent LGDs with an attitude existed in this particular region for a long time.
If anything, Shars were more vicious when I was a child. My grand father had dogs that weren't for touching - for anyone. That was the norm back then. My dad as a child could freely play with dogs, he couldn't go near Shars. Everyone back then knew that Shars are naturally very sharp. I remember hiking as a child in a larger group with my parents, some relatives and friends. As we came across a herd of sheep, I remember very serious dogs marching by, slowly crossing the dirt road with the livestock. Everyone kept their sweet distance and the dogs and livestock of course had the right of way. This wasn't just LGDs walking by, I'm sure everyone in that group stopped breathing for a moment.
If one compares various countries and their respective LGD populations, it often comes down to localized selective regimes. The question to ask is how harsh an environment has to be to necessitate a substantial portion of ferociousness in LGDs. What happens if average LGDs get eaten consistently in a particular region? What happens (longterm) in regions where average LGDs totally suffice to keep the lambs safe (and warm)? Over time the local selective pressures decide the differences in phenotype or temp. The Scandinavians didn't become blond and blue eyed because the vikings wanted to show off their women to their neighbors. It just made more selective sense to let the pigment go. An no, I am not implying Scandinavians are watered down humans. lol
Most regions in Western Europe haven't had a high prevalence of predators for centuries. Ordinary LGDs would be just fine there. Other regions however are infested with predators to this day (You can still buy wolf-furs in Skopje's Old Bazaar for cheap). That will have consequences on the LGD pool. As Ray Coppinger stated, the "cull"-rate in transhumance in that region is phenomenal, only the toughest dogs make it. The life on a farm in Southern France on the other hand is very different. All of this gotta affect the base line in an LGD population.
In Shars, mastiff blood does not have a positive result. It changes the dog to its core. In recent years, people presumably do it anyway for fighting purposes, but that ain't a Shar anymore. And it shows.
I won't speak for Kangals or CO's, mainly because others know much more about their breed history than I do.