Delta did switch around Zones 2 and 3, it used to be Zone 2 was Medallions in the front, Zone 3 Medallions in the back.
I have observed though that on the 767-300, Zones 4, 6, 8 are the rear coach cabin, 5, 7, 9 the front coach cabin.
Jeff
Ahhh, thanks for the info. It's making more sense now!