Can you tell me who these churches are that follow the process that you laid out. The ELCA, Episcopalians, Methodist, Presbyterians and even most Baptist don’t follow those procedures.
HTB has described to a tee most every baptistic church with which I have ever fellowshipped. The SBC, for just one example, is an association. It’s not a controlling hierarchy. Individual pastorates are filled by deliberation of the local body of believers. Indeed, these congregations do tend tob retain their conservatism despite failures of association leadership.
The main threat of corruption, IMHO, in these scenarios is the association seminaries. If they go bad, then it becomes more difficult to find good pastoral leadership. This is essentially what happened to American Presbyterianism early last century. The modernists staged a coup in the seminaries, took the money, the property, and effectively forced those who wanted to remain conservative to flee and form new churches.
Nearly all Evangelical churches and that includes Baptist, just to be clear. I can't think of a single Evangelical church organization that doesn't but since I do not have personal knowledge of every single one I will just say most and leave it at that.