I know something for sure is that history plays its role in the ranking. You have teams that were the best but sold all their players and for one whole season played bunch of scrubs the whole season only to still rank in the top 100 in the world. In other cases like myself, being that I am fairly new, even with last year beating world rank 2000-4000 alot I am ranked in the 7000s. So even if you had the best players in the world and you just started, it would take probably at least 3 seasons to have your ranking be realistic.
Besides history, I think the main thing that determines if you climb up the ranking is if you performed relatively better than the teams ahead of you and vice versa.