I am saying that in order to make the claim "simple universes are run more," you first need the claim that "most universes are more likely to run simple simulations than complex simulations." In order to make that second claim, you need to start with a measure of what "most universes" means, which you do using simplicity. (Most universes run simple simulations more because running simple simulations is simpler.)

I think there is a circular logic there that you cannot get past.