As I read this, I was like, “HUH?!?”
Then you said:
That actually makes sense. Especially if it’s a vocal-heavy album, and the vocals really are the featured instrument. Which is usually the case, anyway.
But you wouldn’t use meters to see overall vocal levels in relation to the rest of the instruments in a song, if you were doing just that one song, would you? No you wouldn’t. Would you? No. Y-no. 