I am always stuck at this point after using insert meshes because the resolution is very high to UV map the model using Uv master.
Check this, I made a space station using insert brushes, now how to proceed next?.
Should I organize the buildings into different subtools and then re topologise each separately, do UV mapping using UV master and create all the maps and export to Max using Goz?
Or is there a better way?
Ok, first… I gotta ask, what’s this for?
A game, movie, short animation project or just an illustration?
**Each one has it’s own process and limitations…
However, regardless of the “end goal” you’ll still have to separate each of those buildings into a different subtool with it’s own UV’s and texture maps *(Normal, Detail, ect).
All of which you can do inside of Zbrush.
From there… well, it depends… on what you want to do with the models.
**Based on if it’s for a game, movie, short animation project or just an illustration.
Its actually for all three 
So yes I have split them all into different subtools, that will help in the long run.
Thanks
Sunny