Well Esme acted alone when she mindwiped Bishop and Sage, and made Sage's mind go into shutdown mode or something. From what I hear about Sage, shutting down her mind is not an easy task. Of course, Esme was hopped up on Kick at the time, so it probably augmented her powers.
Has M had any formal training telepathically? I know the Cuckoos have been trained extensively by Emma, who Jean claimed was the most Machiavellian person she had ever met. I'm sure a Cuckoo would have some ace up their sleeve taught by Emma. I see a Cuckoo winning 6/10.