OK, here's an old chart I dug up.
and here's what was written about those front mics: "... the overall pickup design is based on four spaced, breasted and angled, Main omnidirectional microphones. ... the distance between these hanging microphones is approximately 7.5'; their height above the deck is around 9'. This spread is not typical for arrangements without a center microphone. For example, the downstage microphones in a Decca tree are likely to be spaced less that 7.5'. However, after many years of experimentation, we feel our current Main array produces a useful combination of flexibility, timbral accuracy, and musically appropriate balance for most standard symphonic concert literature."
And that is what I am seeing. I am not saying they are wrong; I am just saying I do not understand such setups, and I can not reconcile them with sengpielaudio.com.