Actually, how about replacing "commander morphs" with "customizable upgradeable commanders"? Could even be added as a whole new feature entry. Or does that sound too much like a shitty action-RPG component?
Imo morphing can't really be considered an "ability", unless it's part of a "morphling unit" that can adjust to situations as needed. There's many more "real unique abilities" if the list needs to be longer: EMP, minelayers, burrowers, replicators, teleporters, ...