Let's say that you saw an executable file weighing in at 25 megabytes of hand-coded assembly running on a modern day Core i7 chip.
Would you really assume that the source code that it would take to write such a program would be over an order of magnitude different if you were targeting a RISC processor instead? Now give yourself access to an expressive compiled language, and estimate how much code it would take. Does the fact that you're targeting RISC even matter anymore, algorithmically?
Unless you're assuming that the biological "instruction set" has some hard coded primitives that make AI an easy problem, it literally doesn't matter at all that the instruction set is complicated (or rather, it matters up to a small constant factor), given that our programming constructs are vastly more powerful than those available to neurons. It's the connectivity algorithms that are important, and biology has absolutely no advantage there.
