But you can see on the pitch he offers so much, and he bridges the gap between defense and midfield so well, the way he holds himself, I think he would be a decent captain as he’d have influence on the side
Indeed and being shy or inarticulate doesn't mean someone is not intelligent. There are all sorts of different types of intelligence, we just tend to think in terms academic and communication skills as intelligence. The traits needed for a football captain are not necessarily academic knowledge or aptitude.
I would have thought a football captain needs to have his teammates' respect, be able to motivate and to get them to follow the managers instructions. Having lots of experience also helps.