mason is right. he's right by such a wide margin that he's deemed it not worth his time to legitimately entertain your idea. imagine a last point with sentry guns overlapping in range so you can't take all of them out with your uber as well as multiple heavies that will also live, and with some of them on the gun that makes you slower.
if you read what i just typed and thought "yep this sounds like a fun experience" then i honestly have no words for you.