I say that one is BEGINNING to stray into Pantheism, because your view does not give creation the ability to bring about secondary causes. Thus, creation is an extension of God which has no inherent ability to act apart from it.
The Reformers simply said that God is sovereign giving His grace to whomever He so wills.
Does God giving man the ability to procreate (cooperate in creation) intrude on His sovereignty? If not, why then do you claim that when man cooperates in the spiritual realm, it infringes on God's sovereignty? If a woman says she can give life through the means that God has given her in the natural sense, what is to keep us from saying that a Christian gives "birth" to good deeds based on the graces that God has given us? That it is "our" work? In both cases, we cooperate in God's creative work.
Regards
Well if this be even the beginning of Pantheism then I would suggest Im in line with both Augustines writings and, as Augustine points out, the plainest sacred writings of the Church. I would suggest the rejection of what Augustine has stated above shows the Church to be out of wack with the plainest sacred writings. This according to Augustine.
Does God giving man the ability to procreate (cooperate in creation) intrude on His sovereignty?
Yes.
Isaiah 42:8
For My own sake, for My own sake, I will act;
For how can My name be profaned?
And My glory I will not give to another.
Isaiah 48:11