Well there plenty of type 3 who are businessmen. And they are good at making decisions based on the evaluation of all the facts. They are pragmatic and detail-oriented so the decisions they make are normally solid ones. They might take a bit more time at taking decisions than a 1A or 1B because they are analytic and are more conservative with decision making.
Navigating social situaitons might be your 2B side that comes out.
The leadership role could simply be that you are an “intellectual leader”. Meaning that because you are good at analyzing facrs and data and are detail oriented and structure, you are effective a having a team do the right tasks. And because you hate bad surprises and hate it when you feel out of control (type 3 traits) being the leader is a way to feel more secure because you are in control of the variables.
A 1A wants to be the leader (or, more precisely, the boss) because he doesn’t deal well with authority and needs to be at the center of everything.
A type 3 might want to be the leader but not to put himself above others but as a way to make sure that things dont get out of hand (type 3 don’t like unexpected problems, issues or changes). Basically a type 3 can want to be the leader to avoid being on board of a sinking ship. He prefers to stear the ship to avoid any possible obstacle.