24y isnt entire humans lifetime ... Nor is 36, 48, or 60 ... and your character can be litteraly anythng in between all of them.
You are taking it from wrong end ... If you will look long enough, you allways find some way this or that will be impossible ... instead try to think about how to make it possible.
In FR, average human lifespan is the same as ours. Characters look about 25-30 years old, so for human characters their looks should correlate very closely to their actual age. If they spend 24 years on building a fortune, they should have started - pretty early, yes. And such a remarkable individual definitely should be recognised by Duke's advisor on sight, because Baldur's Gate isn't that big, population-wise. It's not a Shanghai or Mexico City.
Ragnarok, stop nit-picking at my words, please, it's not funny anymore. The topic doesn't worth it. I don't even understand which point you are arguing for. I'm pretty sure that, whatever goofy nonsense Larian will come up with, their fanboys will swallow it regardless.