Agreed. The tax returns will probably only show more about his foreign business dealings. It also may help gather evidence on misuse of his "charity". It's obvious why he paid off Stormy; to avoid scandal in a close election.I don't think you will. That Trump paid Cohen is not in question. His motivation for doing so (at least legally) is. His tax returns will shed little light on Trump's reason for paying the hush money.
I truly believe Trump never thought he'd win the Presidency. He just liked the limelight and the adoration of his fans. When he won the nomination, I think he was genuinely surprised but didn't think he'd win the election. However some people did think he had a shot at winning. As the election drew closer he and others realized that he would really win it but it'd be close. That's when they started looking at tying off loose ends. Unfortunately for them, that's illegal. What a bunch of morons!