I grew up in Australia and can say that I would rather face a Red-bellied black snake any day over a Brown snake. The Browns are much more dangerous to humans. The Red-bellies usually run for the hills when they meet a human whereas the Browns are much more feisty.
From what I understand, even though the brown is the second most potent snake in the world, their venom is more effective on mammals. The red belly venom is more effective against reptiles. Kind of ironic that the red belly is a lot less harmful to humans (still pretty fucking bad), but a nightmare for the brown snake.
