Yeah. I'm guessing Canterlot = Camelot = capitol = fancy (even though Camelot was arthurian, so probably not that fancy - seeing ponies of the round table would be awesome, BTW), wheras trottingham = nottingham = rural.
As for the fame issue, I'm going to go with the 'not well publiscized' theory. The discord issue was reolved within a day, as was the NNM event. Both of them would hae been noticable, yeah, but there are lots of reasons news wouldn't have spread far. The six could have requested it didn't go far. It might have never been specified who they were. They could have let the guards or the princess take the credit. It may even simply be that they were heard of, but simply not recognized. Granted the names are all pretty unique, but someone doesn't go around fluffing themselves up it's hard to tell if they're famous or just another face in the crowd.
Personally, my theory is that Equestrians like to just let certain unpleasant issues fall into the past. A gigantic, historical event concerning one of their princesses became an old wive's tail, after all, and most ponies had never even heard of a zebra. "Equestrians live with blinders on their borders". If it doesn't concern them, or they don't like it, they seem content to just forget about it entirely. Which is... fairly unsettling, as cultures go.