And yet, there are plenty of examples of current pitchers being successful despite a lack of velocity (Suarez, Lugo, Littel). Movement and command is king.
Tunneling is something that's hard to measure but as important than anything us for those that 'know how to pitch'.
It's a combination of it all and someone like Maddux was a master of all aspects of it which shows how far that can get you. Odds are that Owen doesn't amount to much because most pitchers don't. But if he has command, movement and can tunnel his pitches then he can get big league hitteres out with poor velocity.