A manager with many direct subordinates has a wider than does a manager with only a few subordinates.

The answer that will fill in the sentence is that, what comes next to wider is 'wider span of control'. It is because a manager who has direct subordinates has a wider span of control because he or she has a lot of people to be connected with and to assist him or her in handling things and doing things that made him or her have a wider control rather than those who only has few.