Your weakest hand is pretty weak. Uranus, Nimestiec, C Wing, Cyb Lhia is really bad even though it's an even split. Bad round winning ability and bad life gapping ability, especially if Cyb Lhia is beatent or shut down by SoA.
Plus Stella is flat-out better then Miss Stella even if it's only slightly.
I think it has to do something about making your opponent pill more to overcome your attack or you having to pill less to wall opponents attack or some other fancy explanation I never bothered to grasp fully.
Although in this case, drawing Miss Stella and 3 Vortex burns a pill just to make any use of her ability.