I agree with making it a sequel to SPD, but how I would do it is that the Lupidrangers were uncover SPD officers pretending to betray the team and steal their ranger tech and other things in order to uncover a real SPD traitor. Before they can complete that mission, the officer who secretly assigned them the mission is killed and the Gangler equivilants not only steal a bunch of power artifacts, but also take all the documents proving they were undercover and making it look like they assisted in the theft but turned against each other.

So the Undercover people are trying to recover the artifacts and the evidence clearing them, while the Pat equivilant are the current junior Earth based team who have been tasked with recovering the artifacts and arresting the supposed traitors.

The six morphers were supposed to be from the same team, so the main sort is summoned by both of them and when summoned by both teams pretty much randomly picks one. It's not intelligent; it just wasn't designed for two different teams.

X is another undercover officer assigned to get the supposed traitors to trust him, but after spending time with them starts to believe them.

Eventually the undercover squad is able to prove their innocence in time for the end of the show.

More like they haven’t done a mature season since In Space, Lost Galaxy, Lightspeed, Time Force & Wild Force.

Well Wild Force was and wasn't mature tbh, it had some moments like the stuff with Dr.Adler but generally it wasn't particularly that memorable in comparison.

Different strokes but I find it pretty memorable and it's easily in my top 3 favorites. Its mature in the ways it needed to be.

I've been thinking of the two ranger teams being from different schools.

The thief rangers from a poor environment but getting enough money needing to go to college. The cop rangers come from a rich environment as they go to university.

I can picture Ranger X French who's trying to bring both teams together as one force, showing that titles like thieves & cops don't always define you. Your actions define you as heroes.

What would be good morphing calls?

SS/PR:
It's Morphin' Time!
Kaitou Change: ?
Keisatsu Change: ?