I wasn't aware we were talking about the past-it, 'last fight of his career' version of Hagler. Unless stated otherwise in the OP, I reference the prime version of a Boxer in these types of fantasy match-ups. But, even taking the point you're trying to make on board, Jacobs doesn't move anything like Leonard did and he was at least matched, if not bested, in the battle of the jabs, by an opponent with a reach somewhat less than Hagler's. Jacobs' punch output was nothing to write home about, either; nothing to match the output Hagler generated, routinely. In more ways than one, you are comparing apples with oranges. Have you watched either of the bouts you reference (Hagler/Duran; Hagler/Leonard)? Because, it doesn't seem like you have.