In History much theology began to be ironed out and over time some things became clearer.
The problem in much of the historical theology is they lacked much in the way of perspective.
Before the printing press the historical ideas were more subject to corruption with some of the men being unsaved men. Much discussion of the history is subjective. Those opposed to grace attempt to frame it in a way to is favourable to those points that they reject.
Well, systematic theologies are always subjective to an extent.
I have seen the argument that earlier Chriatians lacked perspective. I think we all do, to some extent, because we are living life. This is the reason we held for so long about why Penal Substitution Theory did not exist prior to the work of the Reformation (the Apostalic Church focused on evangelism, the Early Church persecution, Ansrlm irony out a workable throry but was influenced by the medieval focus on honor, Aquinas ironed out some of that but was Roman Catholic and focused on original sin rather than indi ideal sins, Calvin finished the ironing).
It is logical. One issue is addressed but ither issues not identified or simoly not an issue of the time. So theology is slowly refined. Errors are removed, corrections made, and you have a better version.
But there is another logical conclusion. I tend (as you probably guess) that this process ultimately builds error on error. In my example, what if Anselm's premise was completely wrong, and Aquiinas merely adapted thatcerror ti the understanding contemporary to his time, and Calvin, thinking he was correcting error, allowed his theology to be shaped by the philosophy he had studied in university (Renaissance Legal Humanism).
If the second is correct then Calvin was a move farther away from truth than Anselm (he built on error).
But both are logical. The ultimate standard should be which of any theology most aligns with the biblical text.