I hope you are all well, this is my first time writing on a Paizo forum. About the changes, due to the recent updates, they will remain as suggestions for a future version of Cleric. The Doctrines greatly restrict rather than expand the class, there have been no new Doctrines since the initial release, but there have been expanded Domains and Apocryphal additions. They should come as feats in the Core Rulebook. I think the deities themselves are enough to differentiate the clerics. The cleric should come with the Cloistered Cleric chassi, but with proficiency in light and medium armor and shield block. The warpriest, this should come as an option of a class that could include the Inquisitor. A class less concerned with rites and fervent prayers and being more an agent of the religious institution itself, defender of dogmas and hunter of heretics. Something between the Cleric and the Champion. Who knows in the future a class like this will appear along with the Shifter, which is linked to the protection of druidic circles.
The other classes are fine in my opinion and I'm waiting how the witch will be updated.
I hope I have not offended anyone with my post and my occasional spelling errors. Thanks for reading.