If the movie material needs to come after your prior edits, then yes, I think your idea is the way to go. That said, I hope that this isn’t truly the last outing for Mando in live action. If that turns out of the case, you’re going to have significant rework.

I think you could place a hunting Imperial warlords (and Dr Pershing) movie in between movies 5 and 6. We already ended with Din helping vs pirates, we saw increasing issues with the Imperial remnants near Mandalore, and we saw his growing connection to the New Republic fighter pilot. Now, doing this might require again cutting Grogu out of content, since you would be keeping the reunion to later, or maybe you’d add the reunion to the end of this hypothetical movie.

With that idea, you’d have movie 5 being about fighting pirates and redeeming himself in the face of the other Mandalorians. Movie 6 would be hunting Imperials for the Republic (the Hoth-lite guy and Janu), reuniting with Grogu, and building toward something bigger vs the Empire. Movie 7 would be the Boba Fett stuff and the retaking of Mandalore.

The Hutt stuff could then either be part of Movie 6 vs the Imperials (closer to the vanilla movie plot), or an epilogue as you suggested, maybe a reprecussion of events set in motion in Movie 6 when Mando brought in Janu.