Occam's Razor is not useful in a situation where we lack so little knowledge. Besides that, if a god exists, then the universe's degree of complexity simply is a result of the pre-existing complexity in his mind, and therefore the sum complexity of god+universe is not greater.
Occam's razor is always useful. If you cannot understand how adding a powerful creator god adds a hugely additional level of complexity to the natural universe then I don't know I can help you. We are not talking about maths we are talking about the concept. Of course any god sufficiently powerful to create universes has to be more complex than it's creation.