If it were just a matter of replacing a piece of paper, I agree with you. However, if he only needed a copy of the citation, there would be no need for Lehman to sign a new one. The citations from Zumwalt and Hyland would have sufficed for the Silver Star and Zumwalt alone for the Bronze Star. Lehman could just have signed a cover letter and forwarded them to Kerry.
Since we don't have the dated cover letters or the actual award nomination forms, it is difficult to figure out exactly what prompted Lehman to sign these citations at least 12 years after Kerry left Vietnam and probably longer. I am speculating that Kerry requested that his medals be reissued, which required SECNAV administratively to reissue the citation. In the case of the Silver Star, the citation wording (last sentence) is slightly different from Hyland's, which could just be a matter of changed wording for some of the boilerplate language.
I agree that throwing away the ribbons versus the medals may just be a semantic difference, but Kerry's problem is that he has stated previously that first he threw away his medals, then he changed the story in the 1980s to say that he threw away his ribbons and someone else's medals. According to Kerry, he kept his medals because he is proud of them. He has them prominently displayed in his office. If we discover that he asked to have the medals replaced, then it is no longer a semantic difference between what he meant between ribbons and medals, like he said on GMA today. A request for replacement would be equivalent of Monica's blue dress with the stain.
It is damaging to throw away one's decorations. Kerry could say that he did it as a matter of principle. But the fact that he lied about it is even more damaging. It is the old business about the cover-up being worse than the crime.
I agree that the ribbons vs. medals controversy calls into question his honesty. Throwing away either raises questions about patriotism.