It is really rare is to see fast bowlers as captains. It is a common school of thought that a fast bowler won't be able to guide his team or the other bowlers well if he himself is having a torrid time with the ball or is being hit for runs. Another thing that fast bowling captains need to be wary of, especially in Test cricket, is criticism that they are either under or over bowling themselves.

from Times of India https://timesofindia.indiatimes.com/sports/cricket/news/cricket-flashback-fast-bowling-captains-the-rockstars-of-test-cricket/articleshow/92596798.cms