There are only so many trophy bass in any given stretch of a smaller river.  When you narrow it down even further to a few isolated spots that these guys have bank access to, how could they not be the same fish?

Well, it may be instructive to look up the results of your DNR shocking samples, you'll probably find that there are many more fish in a given stretch of river/lake than you think. That said, there are undoubtedly a few that get caught repeatedly, but most of the fish that get that big do so because they compete successfully for the best food/feeding opportunities, and because they are exceptionally skilled at avoiding predation over a very long time. 

Ive been catching 15-17 in smallies off one small stretch this year. (Not giants, but still nice fish). In 3-4 spots on the spot. Ive thought this, but in examining them, they do not appear to have been hooked previously.