my point is that the classes' names are arbitrary categorisations made for the players. they don't exist to that degree in universe.
it's not like characters have the name of their class stamped on their forehead.
if you met someone who lives in the woods, worships silvanus, casts druid spells, *really* loves nature... you would call that a druid.
just like if i met someone with a white coat working in a hospital and giving medicine to people i would call it a doctor.
i don't check his degree in medicine or care if actually he's a "herbalist with a specialization in hospital doctor stuff"