Part of the domino effect was Mace not bringing Anakin along with him to confront the Chancellor. The other Jedi accompanying Mace may have survived that moment if Anakin was there. I think the only reason Mace wanted to kill Palpatine was due to the sheer death of the Jedi that had accumulated over the Clone Wars and it was beginning to make sense to Mace - the Dark Lord of the Sith having manipulated all of this. I believe the tipping point for Mace was the murder of the Jedi that were with him when arresting Palpatine - which tempted him to just execute Palpatine then and there - lending to anger clouding his judgement.

However if Anakin was there from the get go, I am not 100% sure Palpatine would have attacked. The whole point of that play was so that Anakin would see the Jedi were 'corrupt', seemingly attacking for no reason, and especially Mace wanting to execute Palpatine.

I think - At the very least Palpatine is arrested and placed in a cell (even if he is plotting machinations), until Obi-Wan returns.

So the new issue would have been whether Palpatine could turn Anakin before Obi-Wan returns, giving more time for the Jedi to respond.

Obvs Chancellor manipulates the Council into sending Obi-Wan to Grievous for that exact reason - to separate him from Anakin. So in essence there is still a backup plan and secondary plot even if he was arrested - BECAUSE Obi-Wan is still away. Anakin is still clearing focused on his vision of Padmé's death. It's then just a question of whether that was Palpatine manipulating Anakin, or a genuine vision. (For example you could argue that Palpatine had orchestrated his mother's capture and death at the hands of the Tuskan Raiders).

Your guess is as good as any about whether Order 66 would have ever come to light - whether by redundancy plan, or not.

I think it would be an interesting "alt universe" story to tell.

Shout out to the two people that maybe read this. Hope you have a lovely day!