That may happen in revision waves... but it is rare to have two of the same mould first-released at the same time. I can think of the FOC Soundwave/Soundblaster, and Energon combiner limbs JP Arms Micron Rumble/Frenzy... but they do try to stagger the release of redecos (which may end up together later).
As bad as female TFs toys are to retailers, I'd still hope that these two are different moulds, just as a sweetener to retailers to stock the case.