It seems to me that a good way to introduce different ages of NPC's into a world would be to provide different scaling for body parts. (shorter legs and arms, larger head mid size body &c.) It would be useful to have s model modifier (without having to spend thousands of dollars on modeling software) where the artist or modder would only be changing the proportions rather than having to re-sculpt a model from scratch.
10 - A Masterpiece, Genuinely Groundbreaking 9 - Outstanding, a Must Have 8 - Excellent, Recommended to Anyone 7 - Very Good, Deserves a Look 6 - Good, Qualified Recommendation 5 - Fair, Solid yet Unremarkable 4 - Some Merit, Requires Improvements 3 - Poor Execution, Potential Unrealized 2 - Very Little Appeal 1 - Not Recommended to Anyone