Of two equivalent theories or explanations, all other things being equal, the simpler one is to be preferred.
When you have two competing theories that make exactly the same predictions, the simpler one is the better.
No more things should be presumed to exist than are absolutely necessary.
With all things being equal, the simplest explanation tends to be the right one.
Entities are not to be multiplied beyond necessity.
Entities should not be posited unnecessarily.