You're right, that's exactly what they are doing. This is no different then what they did with Cass as Batgirl with the whole, "She's a better fighter then Batman."
They are really playing with fire when they do this. It might get a few people to pick up the comic, but in the end it just pissses off Superman and Batman fans and cause them to get resentful over the fact that they got to weaken their charecter to make another one look better. And they are right.
It seems they are using a lot gimicks to sell this charecter. I expected this to happen. DC rushed to fast in giving Supergirl her own title. They should have had her be in Teen Titans or JL or something until her charecter was established better and if she was in fact a strong enough charecter to hold a title by herself.
Obviously she isn't, this is why they are having a DC icon like Wonder Woman in the title to help support it.