Joshuabgood (and from another direction josh) is arguing for a hard-edged (pacifistic) dualism, where the line of demarcation between the Kingdom of God and the affairs of men is a stark one. Joshuabgood sees all earthly power centers (archys) and their carnally-grounded coercive methods (no matter how well-meaning or temporally positive) as ultimately in opposition to the advance of the transcendent KIngdom of God. For joshuabgood, there is but one "archy," one methodology, and one King - and "of the increase of his government and of peace there will be no end" - not just in a spiritual/heavenly sense, but in a physical/earthly sense as well. Going back to his early comments about consistency, he believes his is an ideologically cleaner place to be. (The other Josh also has a hard-edged dualism, although his seems to be rooted more in the spiritual depravity and futility he sees outside of the brotherhood of God. Ironically, as an Anabaptist, his approach reminds me of some of the hard-nosed Calvinists I have known through the years
Gary's dualism is not as starkly-edged, but it is "clean" nevertheless because it is rooted in robust separatism. Gary recognizes, in Romans 13 and elsewhere, that the ordained work of God occurs both inside and outside of the household of faith, but nevertheless, the Christian is called to remain distanced and uncompromised from the powers and principalities of this age, not judging or involving themself the affairs of men. Gary's approach is also different from joshuabgood's in that it places more of an emphasis on the spiritual than the temporal.
I believe HK and I have a strong dualism as well that separates citizens of Christ's Kingdom from the means and methods of earthly governments, although it is a bit fuzzier-edged, and more pragmatic. It recognizes the centrality of Christ and His Peaceable Kingdom, which we believe will eventually come in fullness "on earth as in heaven", but it also acknowledges that, until that time, the work of God in a fallen world can also occur "outside the perfection of Christ," including through the police function of just governance (Rom 13). I have argued that while our citizenship remains resolutely in Christ's Kingdom, at times we are justified in prophetically voicing our concern when governments act abusively and unjustly, outside of their God-ordained role (something joshuabgood and Gary would not do - for differing reasons).
I hear brother Ox in support of this more pragmatic approach, but I haven't figured out where his edges are yet - although I'm learning more with each post.