Deploy Page Layout Assignments in Salesforce — Without Redeploying the Whole Profile
You want to push one change — a profile should use a different page layout for an object — from one org to the next, ideally across many orgs at once. The short answer: no, you don't need to deploy the whole profile. A page layout assignment is a single entry on the profile (<layoutAssignments>), and the Metadata API upserts a profile per element, so a profile containing just that one assignment deploys fine and leaves the rest of the target profile untouched. That still leaves the questions every admin automating this runs into: will it wipe my other assignments? Do I need the layout and the record types too?
