Beware the leader who casts himself as a prophet. While there certainly have been, are, and will be some true prophets who lead, it is much more generally the pattern that prophets are not leaders, and certainly not institutional leaders.
Consider the nature of the prophet, as demonstrated in Scripture. Only a tiny fraction of the prophets, whether in the Old Testament or the New, were priests. Priests were the organizational leaders of their day, the institutional heads of the religious system.
Prophets, by contrast, usually criticized the priests and their institution. The paradigm for understanding much of the Old Testament is the conflict between prophet and priest.
Tangentially, this shows us how God uses healthy conflict among His people as a sort of check-and-balance. God carries His plan forward, sometimes in the context of responsible disagreement. God does not want His Body to be free of conflict; He wants it to be free of unhealthy conflict.
One major role of the prophet is to be a social critic. (Other major roles include being a seer and a spokesperson for God.) The prophet is thus essentially an outsider; the priest, by contrast, functions as a mediator between the people and God; the priest also organizes and leads religious activities.
Which is God-pleasing? The prophet or the priest? Both! God sets up a creative and dynamic tension between them, and ensures that neither can set himself up as an exclusive authority.
In our churches, we may not use the words "prophet" or "priest" in quite this way, but the principle is still in operation. A pastor, a congregational president, or other leader is carrying out the functions of a priest.
One who truly believes himself to be a prophet should excuse himself from such leadership roles. Read again the texts of Isaiah and Jeremiah from this perspective. These men were not institutional leaders, but rather critics of the institution and its leaders.