Driving2 brushless motors on 1 esc, forget it.
Sensorless brushless motors use the ripple/back emf to "read" the position of the magnets compared to the windings and adjust the cycle to that.

Sensored ESC/Motor combinations are a lot more accurate in that reading process and can achive better startups due that.

But introducing 2 sets of magnets and winding not in sync.... That's a a recipy for disaster.