This title of head over all of the kings of the earth is something that the Roman bishop desires. Boniface VIII is an example of the desire of popes to have supreme temporal authority. His Unam Sanctam, which proclaims a false gospel of submission to the Roman bishop (as discussed here) is sometimes dismissed from consideration on the basis that its reference to rulers being required to submit to Rome is not meant universally. In fact, the rulers are merely the minor premise, with the general principle being the major premise. But the problem is more acute. The very title of Archon of the Kings of the Earth belongs to Jesus Christ. Boniface VIII can wear his double tiara and John XXII his triple tiara, but that's just jewelry - the truth is that it is Christ who is Archon.
True ministers of the gospel (as some ancient bishops in Rome were), are ministers of God, just as also the temporal rulers are ministers (in a different sense) of God. But the kingdom of heaven is not set up like Gentile kingdoms on earth. There are lords many and kings many, but while we have overseers, we are all brethren and have one Lord, Jesus Christ.
I think this title is sometimes overlooked by my brethren who want to maintain a rigid separation of church and state. With this title, though, Jesus is claiming all temporal to be his. Thus, all the kings of the Earth ought to obey his revealed will and ought to order their kingdoms accordingly.
It's a marvelous title. It emphasizes the supremacy of Jesus even while we acknowledge that Jesus first coming was not to establish an earthly kingdom, but a heavenly kingdom. Nevertheless, the kings of the earth should beware. Jesus Christ their Archon is coming again in judgment. They ought to consider that warning and be ready against his coming.