It's not so much about the neurons, but the systems they connect to. And how they're organized. And how many of them (relatively) are in each component of the b

It's not so much about the neurons, but the systems they connect to. And how they're organized. And how many of them (relatively) are in each component of the brain. And the feedback between motor control and sensory apparatus. I doubt you'll ever get to "intelligence" by building a really fast "brain in a box", even if it has super great transistors.