I have a coworker just like that! Love working together with them, because I have turned my back on perfectionism entirely, so I'm great at making mockups, proofs of concepts and prototypes at a rapid pace. Then I hand them my work and they refine it. Gives them a solid scaffolding of what to do and how it should end up looking, so they're not overwhelmed by pre-planning and considering everything upfront, and I get to not worry about the details. Solid win-win for everyone!