It's no different than how all the smaller states and countries started fighting each other once the Germans, USSR or Roman Empire fell - whatever differences, no matter how small, eventually come to the surface. Once Christians stopped fighting the Crusades, they fought each other over whatever disagreements could be found.
Just take a look at how even Ruger .22 rifles and .22 pistols have become collectable based on color of grip emblems, and size/font changes to stampings, even though they all came from the same place. People will collect anything, and anything percieved as rare increases in demand.