For my first big UE5 environment I decided for a neoclassical/steampunk look so I adapted my materials accordingly.
I've used tiling textures with Nanite displacements, and Decals and UV based masks to add grunge for all the buildings, some parts have 2/3 way material blends with vertex paint masking for more variation. The center building is a hothhouse+hanger from Frostpunk but the observatory and mansion are my own creations after studying many references.
All of the learning resources and assets I used are mentioned here: https://tinyurl.com/28gvudqs