If the basketball or soccer team captain were also a ball hog, they'd have trouble keeping the bench full.
When you become lead, you have to let some of the code go, and the best way I know to do it is to only put your fingers into the things that require your contextual knowledge not to fuck up. If you own more than 10% of the code at this point, you need to start gift-wrapping parts of the code to give away to other people. If you own more than 20%, then you're the one fucking up.
Obviously this breaks down on a team size of 2, but then so do concerns about group and team dynamics.