In general the difficult part of raising and training one of these dogs can be compounded based on the environment where they live. Consider that the Caucasian is a guardian with a pronounced sense of property and they will guard it jealously. So if they have a small place their jealousy of they space may be heightened.  With a larger piece of property such as a farm with hundreds of acres they are more forgiving about encroachment on their turf because their sense of property lies closer to the herd or the castle where the owners (who feeds them) live.

So lets take a CO into an urban environment where we are presented with a different set of challenges such as people walking up the the door, population density, noises, and normally a smaller sphere of protection to defend. This will serve to condition the dog to not react until something is much closer than in a suburban environment where those conditions are fewer. The net result is that the dog will now be more tolerant of those things that it experiences on a daily basis. While they are young they may exhibit some fear tendencies because they don't really know how to address they new situation. It does not mean that they will grow up to be fearful. 

@ Duty1st - In your case I think your dog's behavior is correct.  Please don't over socialize if you really want to bring out the defensive qualities. On another discussion we had here - we discussed the idea that defensive drive has its foundation in fear based behavior. I will see if I can find it and bump it up as it is a very good read.