Yeah, but Tanya is a terrible comparison due to her being wholly unsafe on BOTH of her OH and Low armored wake-ups. And why should only the Mileena's, Cassie's, Lao's, and Jason's be able to reliably full combo punish Alien? If you throw out flip just to always be safe, an Overhead that sets up for great oki game, almost guaranteeing an F134 into another flip or snag, a majority of the cast should be able to punish it. -9 would go very far for many of the Alien vs. rest of the cast matchups.
You act like we're trying to take away Alien's overwhelming pressure, space control, AND mix-up game. It isn't like that at all. Ending everything in an Overhead is just a stupid design IMO. If it was a mid, I'd be inclined to agree wholeheartedly, but it isn't. You've still got the ridiculous normals, air-to-air tail attacks, and the ability to facemelt any cast member in the corner using your acid.