There’s a famous quote in sociolinguistics: “A language is a dialect with an army and navy.” I think the same thing applies here. A religion is just a cult with an army and a navy, because then they can enforce it onto others.

Yes, I think scale is typically what determines strength of control upon individuals. Cults are smaller and thus any charismatic cult leader can exert greater control on his small flock. The larger your religion gets though, the less likely the leader himself can micromanage and exert control, thus leading to the delegation of responsibilities and power.