If you are right on Factor 1 (and possibly 2) the rest is irrelevant. The problem is that others will drag you into factors 3 through 99. All this does is distracts from the core issue. Others will want to cover all sides of an issue, because those issues do impact the variance. But it only drives you to the irrelevant and drowns your Factor 1 argument. If you do things right, you should have only one argument.
So, what is your Factor 1? It isn’t always intuitive. As Leonardo da Vinci is attributed to have said, “Simplicity is the ultimate sophistication” It can take a lot of effort to separate out these factors, to understand clearly the variances and to make the complex simple. The promise of analytics should be to help you identify your Factor 1.
Once you know what it is, don’t allow anecdotal evidences, politics, incompetence, and the difficulty of solving Factor 1 prevent you from taking it on.