Rincewind tends to be terrified of everything... but he does get stuff done. And in "Sceince of Discworld 2", he was the one who orchestrated the entire plot to free roundworld from the elves.

(Although that book pissed me off in other ways. Thermodynamics is just "a theory about gases"?! (That was its explicit justification for stuff for dismissing the relationship between thermodynamic entropy and information entropy))