"The Return of the Green Ranger" 3-parter wasn't even originally supposed to be a thing. It was part of the string of late season 2 episodes that were produced while MMPR: The Movie was still being filmed.
The original plan was for the show to go on hiatus after the episode "A Reel Fish Story" (which I now realize I forgot was another Rocky-focused episode, and one of his better ones since he actually got to be a responsible role model who took charge of the situation during the crisis of that episode), and then return with the last few Season 2 episodes a few months later. That
sorta happened, but the hiatus turned out to be longer than intended because of delays, reshoots, and other behind-the-scenes issues with the movie's production. The show was filmed in California, but the movie was filmed in Australia, so the hiatus was meant to let the cast fly from California to Australia to shoot the movie during that time. But because of the movie's production issues, when it came time for new episodes to resume production in California, the ranger actors (and Bulk and Skull) were still in Australia.
So, simultaneous to the ranger actors and Bulk and Skull filming for the movie, a run of several multi-part episodes were produced at the same time, in which the ranger actors and Bulk and Skull either made only miniscule appearances in, or only appeared in scenes shot without any other the other cast members (as in, they never appeared at the school, juice bar, or Command Center). These episodes were "Rangers Back in Time, Parts 1-2", "The Wedding, Parts 1-3", and "Return of the Green Ranger, Parts 1-3".
Based on the fact that Zedd and Rita are together in the movie, it's probably safe to assume that "The Wedding" was originally always supposed to exist, but probably didn't originally have the subplot of the rangers, Bulk, and Skull being on a school trip to Australia (Gee, I wonder why they were there?) and likely originally had more going on than just a padded-out plot of the rangers repeatedly fighting defeated monsters over and over again via stock footage and being trapped in an old theater while staying morphed (because their actors were still overseas at the time).
"Rangers Back in Time"
barely has any scenes of the rangers unmorphed, and focused a lot more on them as children, in which they are played by child actors instead.
And then there's "Return of the Green Ranger". While there is a LOT of unmorphed footage of the rangers, and Bulk and Skull's actors appear, all of the new footage featuring them was shot on location in Australia. The scenes in the colonial past were particularly shot at Old Sydney Town, a now-closed heritage village.
After these episodes, everyone was back on the California shooting set beginning with the next episode, "Best Man for the Job".
But something else I'm trying to get at with this is that, by the time this string of multi-parters were made, MMPR had already used up all of the Zyu2 footage and most of the Dairanger mecha footage. "A Reel Fish Story" (the last new episode of Season 2 before the hiatus) had Zedd resurrect a bunch of old monsters that were destroyed previously because there wasn't enough usable footage of the final Dairanger monster, which did appear in the episode but only in giant form, because that was all of the footage of it that there was. The remaining episodes really scraped the bottom of the barrel for additional Dairanger footage that hadn't been used yet:
- "Best Man for the Job" used no Sentai footage outside of stock Thunder Megazord and Tigerzord transformation and attack footage, since there was no monster of the day (it also used US-original footage between the two megazords fighting each other).
- "Storybook Rangers, Parts 1-2" used badly rendered stilled images of Dairanger's villain character Shadam as Mondo the Magician, and an unused Dairanger fight against him with the Thunder Megazord, which they could only just barely get away with using since it was a fight scene where Shadam's face was covered by a mask. All other fight footage of his had his face exposed, which thus made it all unusable for MMPR.
- "Wild West Rangers, Parts 1-2" used a Dairanger cactus monster that hadn't been adapted yet but had to shoot new footage of it since most of its Dairanger footage was as it disguised as a human, making only the mecha fight footage usable. Both this and "Storybook Rangers" were thus padded out with filler content to make both into double-length episodes with very little happening in them.
- "Blue Ranger Gone Bad" focused on a clone of Billy instead of a monster of the day, up until the clone was destroyed and then one more unused Dairanger monster was adapted for mainly the megazord fight at the very end of the episode, using very little footage of it.
MMPR Season 2 had pretty much run the well dry of both Zyu2 and Dairanger footage by the time "Return of the Green Ranger" came about, so they didn't have any more unused footage of the Dragonzord and Tigerzord to use at that point. And they didn't commission any new footage of them fighting each other because this 3-part episode wasn't originally supposed to exist. They couldn't have foreseen beforehand the production issues with the movie that would later force them to create this episode as additional filler to stall for time.
