Hi,
The list is a bit too large to post (and then, maintain). With new actors coming-up all the time.
This question has been asked a number of times in this forum. I.E. here’s one for you:
Now, you posted in Feature requests …may be hoping for a list and links of providers in the doc.
The point here is, BJS cannot publish and maintain such a list. You will find some references to ‘partners’ and along solutions/formats that have been added to BJS for integration (i.e. adobe mixamo for char). But beyond that and as far as I know, you should not expect the Team to release an extended list of external providers (for any asset, model, texture, etc…). Reason why I autorized myself to move your topic to the Questions category (sorry if I disappoint you here 
).
But as I said, many people in this forum are willing to share their sources (incl. me). Regarding WoW style design, I’m pretty sure @oriongu has been using models of this type for his project. The link is probably somewhere in this thread (that’s become too huge to find easily 
) May be he can tell you where he sourced his models from?
I’m sure many others can share some links for you to investigate… or else, simply open your browser or ask the AI “Where can I download 3D models with a WoW style (or low-poly)?” 
Meanwhile, have a great day 