Even in computer science a lot of this holds true, and you're lucky if you find someone who both knows the specifics of their niche of the field well and knows how to write clean code.

I once had a quite respectable lecturer working for me, and his code was awful. But that was ok - we knew that. He was hired for his conceptual skills and domain knowledge, and we paired him with a junior developer that could take his raw output and turn them into cleaner code.