This third suggestion is the same as works best for me for organ recordings. KM143 in NOS position; DPA 4090 as flanks (pointing left and right at the maximum possible practical distance of 150 cm).
It allows flexibility to move from one pair to the other with everything in beween.
^ Thinking similarly.. More thoughts on why I gravitate to #3.. more specifically to the wide flaking omni pair aspect of it-
I very much like the approaches that both you guys suggest - relying on the main pair above and behind the conductors head. I'd go with the Faulkner 47/67 plan and hope that it does the job even with the orchestra at 57' wide. Having two pairs to choose from or mix together is what appeals to me the most. Having the other mics set up and recording can't hurt. If the soup needs a little spice it's available and automation in mixing has gotten super easy. Want the strings or percussion to swell? Move the fader.
Regardless of what you choose to use as the main pair or array in the center just behind the conductor, consider including a wide-spaced flanking pair farther out to either side of the main pair. Wide-spaced meaning like 10-12' or so out from the center to either side. If going with the Faulkner array and using your OM1's in that, maybe use the ADKs in omni for the wide-flanking pair if they are the switchable TLs.
Here's the reasoning- The addition of the wide-spaced flanking pair of omnis to whatever the center main pair happens to be will serve to
hedge the bet in a couple ways. First, it's a relatively traditional setup for orchestra recording with a long history of working well and flexibly. Secondly, the wide flanking arrangement will sort of serve in a way similar to spot mics in regard to covering/balancing the breadth of the orchestra, but in a way that is more of an extension of the main array rather than in the manner of individual, isolated spot mics. Its more likely make things more easily managed during recording and in the mix without the typical problems of spot mics, and will preserve more natural stereo and depth cues.
The Faulkner array is not a widely spaced on its own and is really more of a single semi-near-spaced array that uses four channels. It can work very nicely but does not have that same "distributed across the front of the orchestra" aspect to it and is not so much a traditional recording method. Without having used it in this specific situation previously I'd be more comfortable combining it with the wide flanking omnis to increase the odds of everything being covered and working well.
I think it will not only be easier to manage an extended main array type setup than a less-wide main array plus spot mics, I also think its likely to sound better. One advantage of the main array + flanking pair is that the mics are positioned on essentially the same L/R plane, so it's already time-aligned, and it tends to preserve depth cues. I really like hearing the depth cues of the woodwinds being somewhat farther upstage than the string sections and the percussion behind that. Its what sounds real to me and is one of the things I listen for from the audience and in my own recordings. Spot mics tend to flatten the depth cues, which tend to be the first thing to go. It takes a lot of work to get the clarity from the spot but avoid that flattening effect. Also, the wider-spacing of the flanking pair will produce a nice big decorrelated reverberant room sound- making a good hall sound big and dimensional.
If the room isn't great, spot mics might be necessary. You're then in a way reinforcing and recreating things artificially because the room isn't up to it. But if the room is good it will be a lot easier and potentially sound better to rely on a well distributed and flexible main array across the front. There are good reasons for complicating things, but especially as a first orchestral open-recording effort, I'd try an keep things simple without spots except for where they are really be needed.
Any chance you might be able to attend a rehearsal before the recording date? That way you can hear some of the work, determine if anything might really need a spot, listen to how the room sounds, and how the sections interact in terms of depth and clarity.