DMG needs to play a good Luigi. He's beatable, but still one of Wario's hardest matchups. The tornado beats everything you have except ftilt, and is fast enough to hit you before you hit him. It's hard to stop his recovery, his fsmash is disgusting, and he can just space you with backairs while you're hardpressed to do anything. Add to this his pretty good fireballs and he's a huge pain to handle. If they're predictable and like to nair your shield then yes, you'll beat them, but if they mix it up if's freaking hard.
Also, vulnerable from the top, what? I think you need to taste one of his stupid fast upsmashes or uptilts.