I’d probably need to add some corner pieces if you really want to avoid them touching.
I’m going through the same painful process of trying to figure out just how modular to make my environments.
The approach I’ve settled for is this: Make some generic wall, floor, and ceiling textures like you’d see in a game like DooM 3 or Halflife 2. Then create some basic room layouts and texture the walls with those materials. At this point the room will still look pretty bland but **** good if you were making a game around 2003 or so. Next add a bunch of little details like pipes, floor molding, etc… I’ve looked at some of the models in Crysis 2 a while ago and a lot of their internal rooms are kind of done this way. They model out an interesting room and texture the ceilings and walls and floors separately. And this works in Unreal as well since a static mesh can have multiple materials.
I’ve realized, trying to make things too modular either gets you nowhere or forces you to make boring looking blocky environments where everything is at 90 degree angles like what you’d see in Wolfenstein 3D.
It helps to do both, free yourself from tile sets when designing an arbitrary room so you have an interesting layout. And use tiles for things like hallways and detail objects.
But what do I know, I’m still starting anew with this stuff myself.