Heisenberg uncertainty principle prevents perfectly accurate measure of "physical state". So, two brains as physically identical as possible will probably have

Heisenberg uncertainty principle prevents perfectly accurate measure of "physical state". So, two brains as physically identical as possible will probably have (slightly) different outputs. You are right about the definition but wrong about your conclusion. It is impossible to measure 2 brains and be sure they are physically identical. But this does not mean 2 brains cannot be physically identical.