Let's use this example. Position "A" is "God the Father has a Father." This is NOT dogma in the LDS but is a commonly held and often taught teaching there. The LDS would INSIST this conforms to the image of God whereas a contrary view does not. I don't think we can make much progress there..., although I don't deny that our spirituality comes into play here. Now, the LDS won't stop there (any more - it no longer claims to be infallible/unaccountable - above examination). It will welcome investigation of the view via it's accepted canon. And what IS that canon/rule? Well, it's the Three-Legged-Stool. And what IS that "Three-Legged-Stool?"
1. The Tradition of the LDS as chosen, defined and interpreted by the LDS alone. They point to the Apostles and Prophets, and to the Second Testimony (dogmas taught by Jesus but not included - specifically - in the Bible), the "other" revelation. This is always spoken of first and given most emphasis, but theoretically, it is equal to the other three legs.
2. The Bible. But this isn't the Bible as a book, those black and white words on the page (compare with Catholic Catechism # 113 - fasinating). Those can be very misleading and besides, they have been corrupted and we can't know they are original. No, it's the MEANING of those words as determined by the LDS alone that is the rule/canon/norma normans, the "word in MY heart" as the RCC would put it.
3. The Magisterium. God has established His Church (the LDS) and especially guides and protects it (not infallibly, as is claimed by the RCC, the LDS acknowledges now that it can make mistakes but they will eventually be corrected and none will be major). Thus, God reveals Himself via the rulings, decisions, arbitrations, councils and interpretations of the LDS - His Church.
Now, these three "legs" are EQUAL and INSEPARABLE so that WHATEVER is in one MUST be in the others - by implication if not explicitely. Thus, what the LDS has said MUST be biblical and biblically taught. What the LDS Tradition says MUST be Biblical and biblically taught (even if only in the heart of the LDS). It is IMPOSSIBLE, using the "three-legged-stool" canon for the LDS to ever determine that the LDS is fundamentally wrong, since it's canon is simply itself. "A" will be arbitrated as correct BECAUSE "A" conforms with "A". But, it is MY position that this is moot to the issue of correctness, it is simply an indication of whether the LDS agrees with ITSELF (and if other views are evaluated, if they argree with the LDS, and of course they rarely do, thus they are all "apostate."). Interesting, I think, to compare this with Catholic Catechism 97, 100, etc. and it's embraces on 3 things as its rule/canon, each working TOGEHTER, INSEPARATELY and EQUALLY: CC Tradition, the Scripture in the heart of the CC, and the Magisterium of the CC.