Networked X-Plane 12 PCs - Installation

My XP12 simulation has two PCs
No 1 The "Master" running XP with three other supporting Apps to simulate the Homebuild Flight Deck, Navigation and ATC
and
No 2, The "External Visuals" XP12 running three 32" screen 

These are networed together and work fien. My question is :

Do you need to install UHD scenery on both machines?  Since I only use the Master to run the flight deck, I don't need to see outside from this machine. So, I was wondering if  i can use the XP12 Global Scenary only, which would reduce the PC's overhead.

Cheers
Nik