Marakanetz-
Record sets in the 60's and 70's were often mastered so that you could put the records on a changer and still play the set in sequence. So if you n records in the set, and thus 2n sides, the first n logical sides would be placed on separate disks, and the second n logical sides would be placed similarly on separate disks such that 1 and n+1, 2 and n+2, etc were on the same disk. (whew!)
So a 3 disk set in changer order would have sides 1 and 4 on the first disk, 2 and 5 on the second disk, and 3 and 6 on the third. That made it easy to rack'em and stack'em on the cheap, plentiful changers of the time for extended listening sessions.
Changer order had nothing to do with "resting the vinyl". That was never a consideration on mass produced records.