The apparently random pairing of Team Weirdo becomes a lot less random if you realize what roles they all fall into:
Captain Marvelous is already a Red, but for a Milestone Celebration it may have been necessary to get a Red that turns into all the Reds.
Yamato is a rarity among Reds for being the Only Sane Man and the glue holding the team together, a role that often goes to Blue.
Takaharu is the Dumb Muscle, normally the role of the third banana (typically Green or Black).
Kagura as Pink is self explanatory, but she represents the culmination of all Pinks past by literally being a child on the inside. Pink is also a combination of white and red.
Stinger is the Aloof Ally with an uncommon color, making him the typical Sixth Ranger. For an added bonus, orange is attained by mixing red and yellow, completing the theme of everyone having a red-mixed color.
A typical Yellow is apparently missing from the lineup (if you don't count Stinger)... which is actually a subtle hint that GokaiYellow Luka will rejoin the action.
Even their main opponent, Gaisorg, gets in on it, being purple, which is a mix of blue and red.
Last but not least, Doggie Kruger fills the same "Bangai/Extra Hero" role he already did.
None of the Zyurangers appear in this special and are one of only a handful of teams to not appear. Given Rita has ties to their enemies, this makes sense.
Taking this a step further, none of the previous Dinosaur Sentai teams show up (the other two being Abaranger and Kyoruger). But which Sentai show up in the Post-Final Boss? The next Dinosaur Sentai, the Ryusoulgers.
