I assume that they are looking at in laymans terms, and saying that if an electromagnetic motor is 80% efficient, an electrostatic motor could increase efficiency of the remaining 20% by 30% to 100% (86-100% total efficiency).
Not that it makes any sense, but I think that was their intention.
I wish people would just explicitly state they can't believe their eyes that 100% efficiency can be asymptotically reached, i.e. no known law of the universe prevents us from building electromotors that are 90%, 99%, 99.9% etc... absolute efficient.
Then we could just remind them that Carnot efficiency does not apply to electrical / mechanical energy conversion.
This is absurd, detecting that a wrong interpretation is inconsistent (because it would result in overunity violation of energy conservation) and instead of rejecting the misinterpretation of the parent, concocting an even more convoluted interpretation.
All because people refuse to believe 100% energy conversion between electromagnetic domain and mechanical domain is impossible?
Turbosets have been doing this for a long time already, the Carnot efficiency limit does not apply to non-thermal energy conversions...
Still, assuming efficiency can't get past 100%, 100% boost can be achieved only on something that already has only 50% efficiency.