Your proof is flawed. The CPU has access to the complete current program state, and also complete knowledge of its own hardware. A static compiler has neither. Therefore, it's not at all clear that a compiler can do whatever the CPU can do.
Example: the best order to run a sequence of instructions could depend on which inputs happen to be in the L1 cache at the time. This could differ from one execution to the next. There's no way for a static compiler to get this right.
Example: the best order to run a sequence of instructions could depend on which inputs happen to be in the L1 cache at the time. This could differ from one execution to the next. There's no way for a static compiler to get this right.