Your code shouldn't have high coupling, neither should the UI. Organized by role/user, by usage, the UI probably doesn't need to let your users do super-cross-functional things in the same bit of screen real-estate. If the UI does need to let your users do super-cross-functional things in the same bit of screen real-estate then the coupling is really just cohesion + complexity, deal with it.
If you can get rid of UI coupling, you only need subsets of the UI team on the reviews.
And you'll end up adding in UI cohesion while you shake the UI design around.
So separate the bits and find a way to reuse your UI elements, at the very least reuse-by-usage across different role/users (so people can graduate to power user without re-learning your UI).
If an experiment works, something has gone wrong.