What do you think about opening ROTS with Dooku and Sidious discussing their plan, sth along the likes of: “The time is near for the Sith to rise once more, cleansing the galaxy from the filth of the Jedi”
The interrogation scene from AOTC might work, if Obi Wan could be replaced with a hologram of Sidious.
And then cut to the scene from AOTC with the Jedi and the chancellor discussing the (possibility of a) war and why it’s still lasting on. After this establish both Anakin’s visions involving his fear of losing Padmé and the spying on the chancellor plot. And then when the core of the conflict within Anakin is set, let the separatist attack coruscant and capture the chancellor. (off screen due to a lack of options)

How easily the separatist took the chancellor hostage might also work as the excuse for Windu to arrest Palpatine.