To me these two buttons: "Save Changes" + "Update Campaign" look redundant.
There are several reasons that I think we should keep Save Changes and scrap Update Campaign.
(1) the user may be confused by the redundancy - which one do i need to click to get my desired outcome? what happens if I click one and not the other? What happens if i click one first and then the other second or if I reverse them. oh goodness me!
(2) If they are not truly identical with respect to the task that the code performs when you click Save versus Update (IOW if there is inconsistent behavior), then the user runs the risk of losing their work. This happened to me in setting up a campaign with CV2. There is no way a user can remember which changes require Update to render versus which changes require Save to render.
(3) the Save button is more prominent and the Update button is buried - so I'm in favor of the Save button. Plus, it seems more immediately obvious to me what 'Save' does, whereas 'Update' is a bit more ambiguous.