For those who aren't aware, the outfit Tataru makes for you at the start of 6.1's story (Scion Wayfarer's gear) appears to be based on Bartz's outfit design from FFV (or rather, his sprite, not his Amano artwork), which, is appropriate given he's a free-spirited wandering adventurer.

In regards to many NPCs wearing mixtures of gear in violation of regular class restrictions, that's mostly a hold over from 1.0 where gear was (mostly) unrestricted, but you were penalized in a massive stat reduction for wearing gear that was not on a 'recommended' class or level (ARR changed this by introducing class and level restrictions for gear). Many of the NPCs in the game (particularly the original Archons like Papalymo) first appeared with that gear appearence in 1.0 and so kept their mismatched gear appearence (Papalymo was particularly egrarious, wearing tank hands and feet with a mage robe as a THM).

And SE seemed to have continued this with newer NPCs as well. At least the Archons have adopted class-appropriate gear now, if not wearing actual unique gear. So I see this actually gradually changing as time goes by, as SE seem to be conscious about this and are at least trying to do something about it.