My understanding of the episode double numbers has to do with days the show was preempted and the numbering system they used for when the show aired.
Episode numbers for shows airing on Mondays ended in 1 or 6, Tues 2 or 7, Wed 3 or 8, Thurs 4 or 9 and Fri 5 or 0.
So they weren't combined or actual double episodes ... just a bookkeeping way of keeping airdates straight.