>>33311376Honestly, for me Hau'oli still managed to come off as a fairly large place. It wasn't huge like Castelia or Lumiose (for a Pokémon game, anyways), but it did have that "in real life, this would feel like a living, breathing city" vibe. It helped that the streets looked pretty realistic.
Malie, and to an extent Heahea, also felt like decently sized cities to me, especially if you count all the surrounding and nearby locations. The rest were just smaller towns, but I think that's what they were supposed to feel like, anyways (although I do wish Poni Island had gotten at least one more settlement besides Seafolk Village and, well, Hapu's house).
I think places like Castelia and Lumiose went a step further in terms of actual, in-game size because those cities are simply supposed to be that much bigger in-universe, like their real-life counterparts. As a result, they relied less on imagination.