GOOD STUFF, Denver....
Although it's rarely framed in the context of "authority," yeah - the point is, God's words trump man's opinions (as one youth pastor at a Baptist Church put it).
Perhaps there are two dogmas on an issue of importance, "A" and "B" Perhaps they cannot BOTH be correct. IF it matters if one (or either) is correct (accountability - and this IS the "rub", the point of contention), then we've just entered the realm of "norming." Norming is the epistemological process of determining correctness/validity.
As those supporting "A" and those supporting "B" figurative sit down at the table together, as WE ALL do norming, the first order of business (now that accountability has been unviersally accepted) is to agree on a Standard. WHAT will be used as the "measuring stick" (the literal meaning of the word "canon", what in epistemology is called "the norma normans" - the norm that will norm"). Generally, the most sound candidate would be the one seen as MOST reliable, MOST objective, MOST knowable by all and alterable by none, the one with the most historic and universal embrace as reliable for such. The Rule of Scripture embraces Scripture for this role. Scripture then becomes the canon ("measuring stick") or rule ("straight edge"). Yes, in a sense, all at the table are agreeing to subject their views to God's, to regard themselves as under Him, their words under His words. And all others are agreeing to this, too.
In CONCEPT, that IS abiding by this practice. I doubt any arbitration would likely be THAT loose, THAT informal - but that would be ARBITRATION according to it - just so loose as to be pretty worthless. In a similar discussion with LDS, they insisted (and went on to demonstrate) that NOTHING the LDS teaches exactly, technically CONTRADICTS Scripture either - although every single one quickly admitted that LOTS of key LDS teachings are "in no sense affirmed by Scripture" either. So, it would depend on how loose or strict the arbitration might be.
THAT is the classic definition of "Sola Scriptura."
And there you set quite a different standard for arbitration. Not simply "isn't false" but "is true." A LOT tougher. But yes - both IN CONCEPT would be arbitration according to the Rule of Scripture.
This is the issue of "adiaphoron." This is one of many concepts related to Sola Scriptura. SOMETIMES, in the arbitive process, it is concluded that the position in review cannot be adequately affirmed OR denied. (AGAIN, we're off topic here, this is an issue in ARBITRATION). It is "adiaphoron" - a matter in which Scripture is not seen as norming true or false. It may even be declared as being entirely "silent" on that. USUALLY, it will thus NOT be declared as "heresy" or as "dogma."
In some cases, the group may decide to simply end the process there - no definitive conclusion is possible. Or it may bring an opinion - NOT normed by Scripture exactly but nonetheless from implications. Generally, most groups will not call this dogma and not claim such is normed by Scripture. OR it may respond with "pious opinion." In Protestantism, "pious opinion" is a view generally regarded as sound but is NOT normed true or false by Scripture - it is thus PERMITTED teaching (and perhaps even a prescribed teaching of that body) but NOT doctrine (and denying such does NOT make one a heretic or less "Christian"). For example, many Lutherans believe that Mary had no other children than Jesus - and this is PERMITTED. But it is not DOGMA, one may have no opinion at all on the matter (as I don't) or even conclude that Mary DID have other children - they will not be declared a heretic or excommunication or burned at the stake (or in this case, even corrected by his bishop - unless said pastor declares that we MUST believe She had other children, then he WILL be corrected by his bishop).
Yes, it's humility. You hit the nail right on the head. It's a willingness to accept I could be wrong - and truth matters more than my power or ego or lording it over others. It's the humility of saying God's words trump mine. It's even the humility of saying, "This is MY pious opinion - that I think sound - but I do not claim GOD teaches it."
You've pretty much got it, my brother.

And thanks for chiming in!
Blessings!