I’ve just gone through to check the feasability of this, using the always-excellent technique of editing/planning from back to front. You start with the end, then you work out the pieces that support all the payoff you get there.

So with that, movie 4 opens with Andor and Melchi on Narkina 5 (having escaped the prison), slowly making their way back to Niamos. Vel (on Luthen’s behalf) puts the hit out on Andor, increasing the threat for him and throwing more shade on Luthen’s character, which we’ll explore this arc.) While that’s happening, Maarva has fallen ill, and is being looked after by Bix, and Luthen is notified. He goes to meet Saw, kicking off the cat-and-mouse with the Imperials regarding the Kreegyr storyline (including Luthen’s fantastic speech), which compels Dedra to capture and interrogate Bix. Mon Mothma has her side story about pimping out her daughter. Maarva dies, which then draws many characters to Ferrix in hopes of capturing Andor, leading to the conclusions. I can envision that as one nice coherent content chunk.

Movie 3 then is as above, but without the elements mentioned here.