It would give you a new vantage point. If you only owned one vehicle, all you would ever know is that one vehicle, what it looks, how it performs, etc. If you only ever owned a Windows computer, all you would ever know is Windows and Microsoft.
But something happens when you own and use two very different vehicles, like an SUV and a motorcycle. You end up learning that "under the hood" and under the exoterica of outer framework and appearance is the same engine that works on the same Newtonian principles. When you have tinkered with both a Windows computer and an Apple computer, you end up realizing that beneath the software architecture is the same esoteric components and electronic principles.
Having two spiritual systems simultaneously, especially if they are from two very different cultures, would help you in a few different ways. It would help free you from your own cultural myopia. It would help you learn that beneath the outer exterior cultural differences of language, cultural symbolism, are the same principles. That's if your mind is able to juggle two different systems and keep then different, as opposed to mixing and merging them into meaningless mud and feel-good sentimental New Agery.
Realizing that under the hood of all automobiles is the same basic engine function (motor, fuel injection, combustion, pistons, etc) then gives you an advantage over others: you learn how to tweak that engine to make it work better. Same with someone who understands how the components of a computer works. They learn how to tweak their computers to make it work better.
For example, if something like West African Vodun works at summoning and working with spirits, and if something like European Goetia or Solomonic Magic works at summoning and working with spirits, then under their external exoteric cultural framework, what are the common, universal principles at play, that make both work?
