I was thinking of 2 cards ORTF and a omni (?) in the middle.
The microphone angle and spacing of ORTF is optimized for two microphone channels using a pair of cardioids. When introducing a third microphone in the center, you'll want to increase spacing or angle of the outside pair or both, unless you are using an omni and low passing the signal with the intent of only reinforcing the bottom octave and a half or so. Otherwise the stereo width will collapse towards mono significantly, and you might also hear comb-filtering from too much "bleed" of similar content across the three channels when mixed down to two. Nothing wrong with using the center mic to only reinforce the very bottom- that preserves "ORTF-ness" and maintains simple 2-channel stereo microphone technique above the low bass region- but to my way of thinking it discards a lot of the potential goodness a center mic can provide.
More optimized options-
Double the standard ORTF spacing and angle the mics further outwards (point them 180 degrees apart facing directly to the sides).
Triple the ORTF spacing and leave the mic angle the same.
Quadruple the ORTF spacing and PAS.
The less ideal the acoustic / further back you are in the room, the more a more narrowly-angled but wider-spaced configuration becomes advantageous. If you change one thing (spacing, angle, number of mics) you also need to change the others to compensate.