Mind and body are one. Without one, you don't have the other. I would think it would be a better view to see them as equal. Kind of like how a processor is useless without memory and some sort of storage device.

About steroids...this was based upon manipulation of the body through means of the brain. Steroids do not directly impact the brain so as to make the body larger, but they impact the body in full. Even if it were so, then steroids we only be another medium. A specialized means within a broader, much more generalized scope.