If there are aliens, and if knowledge is only trade-offs of semantics, it seems that unless you ever met an actual alien, your belief in them must come from yourself. That is, you have a psychosis.
Also, if these aliens are from a simpler universe, how do they understand a more complex universe enough to make things in it – especially when knowledge is merely a trade-off in semantics, or because you can only know what is simpler than your own mind, and their minds were conditioned by a simpler universe? It’s more likely that they would come from an equally or more complex universe than our own.
The current version of natural evolution implies exactly this: that the most complex items evolve naturally from the simplest. Given a random set of atoms, molecules and temperatures a brain can pop out after billions of years of self manipulation of matter. Hence something that is not even alive, let alone “intelligent” blindly creates the highest intelligence. A very simple thing can create a very complex thing.