Selvarin
Explorer
But that's only a (debatable) point for previous editions. Where are all those high-level NPCs in 5e books, now that a century, two land-altering catastrophes, and a magical plague have passed? As I said previously in the thread (although it's now well buried pages ago), a look-through of the gazetteer of the North in SKT shows that the area is now filled with commoners, nobles, scouts, tribal warriors, and veterans, with only a few more powerful NPCs scattered about (a couple of archmages in Everlund, a random vampire, and some dragons)...
In other words, most of the egregious examples are long dead-and-gone, between the effects of the Spellplague and a century's shift in the timeline. So if you want to put in your own exceptional NPC's--a high-level lord-in-waiting or a rogue wizard--they won't be jostling with anyone else's in all likelihood. Now if they exist you know it's your own doing.
Even with that out of the way there's still the debate over 'commoners' with PC class levels and how many there *should* be in a given population...which is rubbish. the ratio is dependent upon what matters to you and your world. It's just a nerd fight, otherwise.