Priming industrial terrain (Necromunda) in neutral grey

For industrial terrain like for Necromunda, the main technique I see people using is priming in black (and often a zenithal highlight) and then going over that in multiple layers of basecoats, washes, drybrushing, etc.

Does anyone prime in a neutral grey followed by a dark wash? Quite curious about this, as priming in grey is a pretty traditional painting technique for minis and seems much more suited to big batches of terrain. Zenithal highlighting for big terrain tables seems like unnecessary time / paint when (real life) ambient lighting is probably a much bigger factor for terrain...

Anyone out there priming in grey, or tried both methods and can give some practical feedback?