Monte,

A congregational church structure would have a minimum of hierarchy. Congregationalism arises out of the Reformation.  Adventists have the most hierarchical church  structure of any denomination with a very few possible exceptions.  Why do you say hierarchy is not Adventist? We are not congregational.

We have a very simple and flat eccliseology: Essentially Elders & Deacons. But we are very hierarchical where it matters most: Money.  Who owns the buildings and who pays the preacher?  Not the congregation. Our hierarchy is not built on equality either.  In fact Seventh-day Adventist church government is a crypto-complex hierarchy that very, very  few Adventists understand, let alone participate in.