Typical Drift-Down profiles that I've done the number crunching for utilise Vmd for the dual purposes of (1) Minimising Rate of Descent to reduce/delay traffic conflict, and, more importantly, (2) Achieving the maximum possible ceiling with view to clearance of high en-route terrain.
Cruise at Vmd and MCT might be at a higher level, but the fuel economics stink, but an acceptable stink if high terrain is a concern.
Good policy is to use the Minimum Rate/Maximum Ceiling technique until such time as traffic and terrain are no longer a concern, and to then increase speed to Maximum Range Speed allowing the aircraft to drift down to the (lower) highest level available at Max Range