I am not talking about early game laning, I am talking about a fight to the death between the two heroes.
even late game, unless butcher gets a lucky charge into furnace he can't kill because leoric can life steal outside of melee range and butcher can't. the only thing leoric has to do is Q and walk away when butcher brand comes out. Then the fight is reset except butcher is almost dead and leoric is almost full. Unless leoric just stands there and eats right clicks for an extended period he comes out on top.
Not to mention imposing presence, hardened shield or even the lvl 20 death march. Even if things go badly, leoric can just wraith walk away.