Some think Brawl is lazy, but he prefers the term 'efficient'. He thinks there's a simple solution to every problem, which most of the time means blowing up the problem. When required to though, Brawl will put forth the energy and intellect needed to come up with strategies that cause the most pain... and make the most things go boom. 

Brawl is that fun character that looks dumb and sounds dumb, and probably is dumb, but has moments of clarity where you realize there's more to them than meets they eye (ha). To me, David Sobolov's interpretation of Brawl from the 2007 PS2/Nintendo DS game is the quintessential voice for the character, but I'm certainly open to other interpretations that you as voice actors might come up with.