While this does not address the issue with the outfits, the mod NPC Control by Paulson limits the amount of townies that the game generates. It works best if you already have a lot of sims that look good in your world, or you could download sims from the gallery that has good looking outfits, place them in your world as unplayed households and the game will pick them instead: https://www.npccmod.com/
The mod have worked fine for me but it can sometimes cause last exceptions because the game is trying to use a sim for multiple roles, especially with roommates in Discover University. I tend to remove it from time to time so that the game can generate some townies, then I add it back and change those townies in CAS with cas.fulleditmode.
