The 1965 Solti is widely considered one of the best Opera recordings...surprised you think it is not. I found the localization of the singing to be superb and especially the depth in the recording and the fact that you can clearly hear the performers are behind the orchestra as is standard for Opera where the orchestra is down in a pit in front of the stage.
I really don't get how that's behind. Also for operas I sit above and opposite the stage, so I am looking down at both from a distance and they should both be reaching me at the same time.
Orchestral seating is usually different and back and front can more easily be sensed