I guess the Cowboy Junkies on Trinity Sessions were just an artifact of the recording engineer and their positions had nothing to do with what I hear concerning their placement on the soundstage?
They used just one mike and sat or stood around it while playing. Any decent setup will show their position and height differences. This is old news.
Sounds to me that whoever said that doesn't have a good enough system to show a proper soundstage. That's not accounting for what an engineer can do by moving performers (and instruments) around the soundstage and even then, the height can vary.
There are omnidirectional (picks up from all directions), unidirectional (mostly from one direction) and bidirectional (from two opposite directions) mikes that when nothing is done to alter their intake, will allow playback of approximately what they heard. That includes height.
All the best,
Nonoise