IMO, there are, throughout the series, a few thingies that make an Amberite or Chaosite chap "advance". Gaining knowledge about the Primal Pattern, understand that this is not the only possibility (IE, Corwin's pattern), a Chaosite understanding something about Pattern, an Amberite learning something about the Courts. I think that's the real advancement NPCs have got, wisening up to particular facts. It is easier, as you don't have got to keep track of a whole load of numbers and shit, and it is harder, because you've got to remember who know what and make them act accordingly.
Plainly put, in Amber, more than in any other game (even bloody Cthulu), knowledge is power. And while it may be tempting to assume that all Elders've got the whole knowledge base from the beggining, it is much more interesting to develop it through the game, thus making them, in a way, advance.