The use of the suffix -ling, in Ardling and Tiefling (like Halfling) is I think maybe meant to make them more cutesy and lovable and accessible little devils and animal/angel people? The impression I get is that is meant to appeal to peeps who probably want to play as Tabaxi or Enueru or whatever, but instead they get an exalted Cat-headed person or a idyllic Dog-headed person, as like an expedient consolation prize that's easier to fit into a catch-all archetype lol.
I always thought Tief was a bit silly as a name. They took a very archaic word for "deep" and made Deeplings from it I guess, but until they show you a picture or start using synonyms for devils and demons it sounds somewhat goofy and doesn't conjure a particularly menacing visage for me.
Ard as a prefix connotes burning from the Latin, but I guess like a good celestial passionate sort of burn in this case, which we see in words like ardent or ardor. As a suffix -ard is much more common and pejorative. Examples listed from the wikti are like coward, dullard, drunkard, and curiously for our purposes wizard. But it also makes a sort of sense, if you figure a Wiz-ard probably wasn't a great thing to be in the middle ages, compared to say a Sage or Philosopher or something a bit more flattering. But they're using it up front, so I get fire. I feel like they definitely left a couple beasts out though. We can rock a Nick Bottom celestial jackass I guess, but they're missing the Bull and a few others I expected to see. To me the Goat would more properly be an Infernal avatar, (I mean kinda obviously right?) but they're up there next to Cats. The serpent, again, an infernal classic, but they don't seem to have paired off the lower planes so they mirror the upper ones in that way. Maybe they'll flesh it out more in days ahead?
