agender people are taxonomically nonbinary and most nonbinary people are trans (except for maybe some of the handful of kids raised by tryhards, but that's probably rarer than the people who had an error on their birth certificate that turned out to be prophetic)
we identify as the more specific labels because they're useful.
when i hear that construction i assume there's a little more to it if you were the person's close friend but it's not practical to go through a whole dissertation on microlabels and exceptions or qualifiers when we're just passing acquaintances.