Is DensGlass and RedGuard a substitute for vapor barrier + backer board + membrane when tiling shower walls?

My understanding is that when tiling a shower wall, the standard preparation process includes:

1. Install a vapor barrier
2. Install cement backer board
3. Apply a waterproof membrane

(This comes from https://www.lowes.com/n/how-to/prep-shower-wall-tile)

Is an acceptable alternative to do the following?

1. Not use a vapor barrier
2. For the walls, use DensGlass instead of backerboard; only apply backerboard at the shower pan and about 1.5 feet up from the floor
3. Coat the walls with Red Guard; use a waterproof membrane at the bottom of the shower pan.