Understanding the origins of many belief systems, I came to understand that monotheism was only the worship of an all encompassing Supreme Being for those who’d previously had and accepted a complete enough pantheon. Some of these people can combine all gods into one with some success. What happens in most cases, and certainly in the second generation, is that one or a few limited gods in the pantheon are elevated to supreme status, based on the egos and greed of the leaders. It is a much faster track to creating a large bloc of fanatical followers than was possible in polytheism or panentheism.
It would be more difficult, for instance, for me to get away with proclaiming that no other Orisha but Shango was important enough for me to worship, so everybody should be a warrior and follow me in destroying those who worship others. I would be laughed out of the circle. If however, I created a new religion in which I proclaimed that since all Orishas are just manifestations of Olodumare, there is no point in honoring each one individually, this would work for awhile because we are already taught that all divisions are illusions (managed by Eshu). Eshu would then become a devil who deceived us by creating illusions instead of a necessary force of Nature that keeps things running in a life sustaining way.
This would work for awhile, but eventually it would become clear that the aspect that is known as Shango would rise in importance because this is the part of Nature that wins recruits and destroys opposition. In time, rather than an all encompassing Olodumare with many facets, we would be worshiping a very unbalanced and over prioritized Shango.
All that I ask of any monotheist is to think about their faith less blindly if possible. If one is going to have one god, to have a whole god who does not need blind faith, and needs no unnatural interventions to provide, since Nature provides all we need already.