The much-disliked sunglasses morphers actually do make sense from a practical standpoint. If your transformation requires an elaborate kata, having your Transformation Trinket far away from flailing arms means you're less likely to drop it mid-morph.
Until you remember that in the original Gekiranger, their morphers were the black gauntlets strapped to their wrists as part of their Ranger suits. Some reason they couldn't have stuck with that?
Also, according to their Super Sentai's counterpart character page, Theo's counterpart's actor had a twin who showed up in an episode as his evil twin and RJ's counterpart was his in-show brother. Suddenly Lewin makes so much more sense...
When Power Rangers Jungle Fury aired, I knew a lot of people who considered Red Ranger Casey the Scrappy, mostly due to his constant wangsting about being a rookie who gets everything later than his more experienced teammates. Then it hit me: Casey is a deconstruction of the Rookie Red Ranger trope as, unlike past Rookie Reds who jumped at the call and quickly adjusted to their roles, Casey showed to have actual concerns about his own progress (not being able to catch up, being the last to find a master, etc.) And by the finale, he's finally got his act together and is now a Martial Arts instructor! Bruce Kalish may get a lot of flack, but you have to give it up to him for this one. -LLSmoothJ
Master Mao's spirit is of a cat. All four of his students' spirits are also all based on cats, Casey the Tiger, Theo the Jaguar, Lily the Cheetah, Jarrod the Lion.
RJ's Wolf Spirit can create a duplicated version of Tiger and Jaguar Spirit to combine into Wolf Pride Megazord. RJ's colour is purple. Purple = Red (Tiger) + Blue (Jaguar).
This might also be a matter of Student teaches Master similar to how the three learn how to acquire the other spirits and zords of their respective masters, he probably learned how to channel their animal spirits too.
A flashback scene of a Power Rangers RPM episode shows a Jungle Karma Pizza restaurant, indicating the world the Jungle Fury Power Rangers fought so hard to protect from Dai Shi's forces was the same one to be later devastated by Venjix's forces. Did the Jungle Fury Rangers manage to keep their town safe until the RPM Rangers destroyed Venjix or were they destroyed?
Don't forget that the Power Rangers Samurai crossover with RPM established that RPM took place in an alternate universe. While this was done for utterly moronic production-based reasons (they stated the two universes had different atmospheres to explain why Ranger Operator Series Red couldn't de-morph, when it was clearly done because they could only get Eka Darville to commit to a voice-over rather than an actual appearance), this ends creating a more hopeful outcome for our Jungle Fury heroes. It's possible that Jungle Fury takes place before the universes were split, or that elements were able to cross over from one universe to the other (Jungle Karma Pizza franchise, anyone?).