It just seemed like one or the other for Aribeth's character would be enough. Shapeshifting is a pretty extensive and useful power. I can understand having other skills to supplement it like fighting ability and tactical knowledge, but in addition to the power she ALSO has a pretty lengthy and huge range of personal skills. It just seems like her character can do every single thing possible and that doesn't seem like it would make for good teamwork, at the very least. She's basically Batman plus Mystique. I just think going with one or the other would be a much more logical and less overpowered choice.