Typically in attaching the drywall to the wall, some type of nailing surface is needed to attach the drywall and tile substrate. So add in framing members where needed.
If you are putting in shower doors that attach to the walls, three studs next to each other, or one turned sideways, make for a wider area for the shower doors to attach (rather than just the 1-1/2″ edge of a stud).
In Steve’s video in BRT, he shows the attached drywall and attaching the tile substrate at a tub.
Go to Lesson 4 – “Bathtub Surrounds”
then go to “KERDI BOARD”
then go to “Three Wall Surround with Prefab Niche”
Starting at about 16:30 in the video, he shows dimensions for wall substrate (in this case Kerdi-Board) meeting up to drywall. You can see the studs where he is working.
Hope this helps! Good luck and let us know how it goes 🙂