It wouldn't in this case. Like I said, I'll blame both.
But it would. You're forgetting about Manafort's ability to appeal here. Allow outside factors in, that makes it so much easier for Manafort to just have the whole thing dismissed on an appeal as you can't just be selective like that.
Like, I perfectly understand how you feel. It's insane how lightly he's getting off. He does not deserve that light of a sentence, at all, and it's crazy he's getting one. But that's on the first judge. Giving a heavier sentence than one would otherwise just because of another judge's failings is not magically justice. Either a crime deserves a particular sentence, or it doesn't. That justice was not served in one instance is not reason to create further injustices by giving a heavier sentence than one would otherwise to try and "make up for it" or whatever. Justice is supposed to be blind, and for good reason. And what you're taking about is the opposite of that, and I myself would have to argue that Manafort would be fully justified in an appeal of such a sentence in such a situation.
I nonetheless get how you feel. But piling wrongs on top of wrongs would not be the appropriate answer here.