"...Woltz's only mistake was not giving Fontane a role that Fontane (and Vito) thought Fontane deserved."

But didn't Woltz also think Fontane deserved it, on acting merit at least? Remember what he said to Tom: "That part is perfect for him..." Aren't acting roles supposed to go to who the role is most suited for?

Let me tell ya somethin my kraut mick friend!