Frame versus language. Do not collapse them into one workshop.
Positioning decides the market frame. Messaging writes the words that express that frame. If you start with copy, you get a clever line in the wrong aisle. This page is the definition. The worked comparison is next door.
Positioning answers “which aisle, versus whom.” Messaging answers “what we say, with what proof.”
On /blog/positioning-vs-messaging — when to do which, in what order, with examples.