Because WoW requires the same levels of concentration, dedication, skill and technology as driving a formula 1 car....
I'm pretty sure Michael Schumacher can still drive like a pro on a regular car.
I use a MX518 and it more than fills the quota. If I need more buttons in it then I just use modifiers, like CTRL and ALT.
However, based on the two options offered by the OP, I'd say the Naga.