It does! Especially since its alluded that Harchefant isn't that old. From below average human height to towering over the majority of them in a short span of years.

I believe the honor of youngest adult elezen we know goes to Jeromere, a Sharlayan student in the Studium quests, who is 20. (After that is Francel and Guydelot at 22.) So they definitely have a busy few late-teen years, that's for sure.