Don Vercetti was not comparing Tony to Hitler on a mirrored or side by side basis. He clearly stated that Hitler was evil on a larger scale. Hitler was a very evil person who would stop at nothing to achieve his personal goals. And in doing so he destroyed thousands upon thousands of lives. Tony Montana was also an evil person who would stop at nothing to to achieve his personal goals. And in doing so he destroyed many innocent lives. Evil acts on the same level? Not by any means. But the bottom line is that intentionally taking a life for personal gain is wrong, and it is evil, no matter on what level it is carried out on.