I'm not sure if that's the case, the list appears to be chronological. "Revival theatres" suggests it's about 1981 re-release. Not sure about the DVD part though, maybe it means 1981 dub was on GOUT.
Does your dub have someone reading crawl text? If yes, maybe the reader says "Episode 4..." in Japanese?
Also, I think your dub is either the first, or second one. 3,4,6 were made for some TV broadcasts, and 5 is on Blu-ray, so it's special edition.