So, if I may shorten your answer it appears you are saying that believers submit in the same manner that they are saved...in that God is sovereign over their submission but they still are the ones who do it.
God is sovereign.
Humankind are submissive.
The believer has two natures (including all the attributes) that war with each other for dominion. That nature which the believer "feeds the appetites" in submission, will determine by the strength of the attributes of that nature and the sovereign of that nature the power and authority over the believer.
God as sovereign has established judgment and justice according to the law in matters that concern the old nature.
God as sovereign has established all characteristics and tools for the nurture, growth, security, ... in matters that concern the new nature.
Thus, if a believer doesn't submit then the ultimate reason is because God didn't grant him something he needed to submit in that moment...whether it be a 'depth of conviction, a temperament, or some influence.'
It could also be that the god of this world appeals to what the believer is most weak. (Paul uses remarks such as this)
Also, do not neglect that the believer is to
"put on the whole armor of God, that ye may be able to stand against the wiles of the devil.
For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places."
Thus, the question becomes clear, why would God pretend as if he wants you do something while not providing you what you needed to actually do it?
First, God doesn't pretend but acts with purpose and plan.
Second, God always wants humankind to do what they cannot actually do. Keeping the ten commandments is an example of the principle. God's benchmark in every area of living and life is never less than excellence. That is why it is all of Grace and not of works (concerning both salvation and living). Paul recognizing that principle states "... no condemnation to them..." God rewards the "good and faithful servant" not some attainment of a benchmark.
Why call you to submit without giving you the temperament to do so, for example?
It is not a "call to submit" but a state of submission. The believer does submit to the old or the new nature. There isn't an in between or third state or land of indecision.
Moreover, why hold you accountable for not submitting or give you reward for submitting when in reality HE is the determining factor of whether or not you actually submit?
There is accountability in submission to the old nature and accountability in submission to the new. There is reward for submission in both the old and new. One is either submissive to the old, or the new.
The war over the direction of submission is according to which will is feed.
If one feeds upon the things of this world and partakes of the influences, excesses, contrivances and essences of the god of this world, then the submission will be toward the god of this world.
If one feeds upon the things of the God of heaven and partakes of the influences, excesses, contrivances and essences of the God of heaven, then the submission will be toward the God of Heaven.
Certainly God is the "determining factor" in that He has provided all that is necessary. That is why He provides the armor of God which is vital, and why the mind of the believer is to be renewed by the Holy Spirit and Scriptures. It is why strict, undistracted, and uninhibited communication to, through and from the Holy Spirit is paramount. Why the power and will of the flesh and fleshly must be crucified daily. ...
The believer must submit to the authority of God and put the armor on, must submit to the mind of Christ by meditation upon the Scriptures that they may "prove what is that good, and acceptable, and perfect, will of God," must submit to the slightest impulse of the Holy Spirit in discerning what is of the flesh and fleshly...
This system is flawed at its core because there is no basis for man's independent will, thus leaving God's will conflicting with itself.
I think part of the problem in understanding submission and the two natures is common to those who desire what is not availed to any person.
It is the same desire as what was presented to the woman in Eden. The "independent will," unbounded by the perimeter of Eden and independent of God, is attractive because it would make us "as God" having dominion and allow the "me" to "decide."
There is no independent will (as much as some would desire there to be) or mere man could keep the commandments of God from birth to death making the cross of Christ unimportant. Salvation, in such a scheme, would solely be based upon the will of man without regard to the nature including the will being "condemned already."
Because "all have sinned," it is evident that there is a lack of an "independent" will and that submission to the fallen will of man is the very best and only direction fallen man has - even with the dire consequences it brings.
God instills a new nature and the believer has then a new will that immediately (even during conviction) wars against the old will.
That is the war. Not God's will in conflict with itself, rather God of heaven's will in conflict with the god of this world's will. Again, "We wrestle not against ..."