We don't know any physical processes that allow to compute Turing-incomputable functions. An assumption that the brain uses such a process is not based on any positive knowledge.
Argument from ignorance is not as well known as other fallacies but very common in discussions about sentience, consciousness, and computability, i.e. not having evidence for something doesn't mean that thing is false. It is possible there are physical processes that are not computable & not being aware of such processes doesn't mean the alternative (everything is computable) is true.
So instead of making any unjustifiable claims like "everything physical is computable" you should instead just say "I believe consciousness is computable and that is why it is possible to instantiate it on any computational substrate, including strategy games like Age of Empires, properly arranged dominoes, and water wheels".
OK. I know that we haven't found any processes that violate the physical Church-Turing thesis, and I believe that we will not find them in the brain that got intelligent enough only after scaling to a hundred billion of neurons and hundreds of trillions of synapses. And, BTW, we don't have theories (except the controversial Orch OR) that allow such computations.
So instead of making any unjustifiable claims like "everything physical is computable" you should instead just say "I believe consciousness is computable and that is why it is possible to instantiate it on any computational substrate, including strategy games like Age of Empires, properly arranged dominoes, and water wheels".