But honestly in 4e my lived experience I describe with some of my feats or powers I select as such. But in the original zone no such expression was available aside from casters getting spells and fighters gaining magic items.So, originally classes were BOTH broad starting points AND narrow pre-defined concepts. You got to choose one or the other, and then it was expected the character would change and evolve with 'lived experience' (which was generally a much more significant thing in early play).
And while they definitely were not player controlled = as a DM I was asking players what kind of magic items and spells they wanted for their characters all the way back in 1e.
Having "Grand Masters" to train heros be part of the story is rather a fun idea like how Cu Cuhlaine gained his feats and such.4e was interesting in the sense that its dense grid of options meant that lived experience could be subsumed within the system. That is you could simply use the build rules to basically reflect the things that happened to your character or that he accomplished. In some sense it is a complete realization of this early scheme.
Notice, when I designed my own game I took this to the logical extreme. There is a dense 4e like set of options, but you literally always acquire them through narrative play, there is no advancement as a separate concept where you pick things. ALL of your character is acquired through acquisition of stuff/experience/revelation. It is the whole essence of the class concept, welded with treasure/experience/items into a seamless and highly directed whole.
RuneQuest had a system of advancement where your skills advanced based on things happening entirely on camera. But I am not sure everything must be "on camera" is valuable.
It really turns up the DM gating of what you can have even more than typical.