evidence confirms biblical depiction of Edom

I require a little clarity of terms in the present discussion.
How are we distinguishing "kingdom" from "tribe"? If it is based on the installation of a leader over a group of people, then how is a "king" in the biblical language at all distinct from a tribal chief? Based on the archaeological evidence, we have reason to believe that the Iron Age settlements in Palestine were little more than fiefdoms; certainly not the centralized powers that the Bible presents them to be.
Even if the Edomites had formed a society by the 12-10 cent. BCE, so what? This only confirms that the biblical accounts are correct regarding their presence and nothing more.