Is it better to carve out your world with sub brushes?

Hello, Please see this image:

Basically what I did was start with a huge 40,000k xyz additive cube.

Then i made a smaller room which you see in the image out of 2 subtraction brushes that are touching.
I want to make a simple indoor dungeon like Kings Field, without using 6 brushes for the four walls, ceiling and floor.

Is my technique a better method since a basic cubic room would only require 2 brushes rather than 6?
I am honestly having some issues with texture alignment.

Thank you for the help.