There's always gonna be at least some resistance (albeit small) because bearings have friction which develops heat even in a new compressor. Of course, with the electric clutch disengaged (which is the case if shes too low on freon) there's far less resistance as its only a couple bearings involved versus if it had Freon and was working in which case youre having to turn a compressor against wayyyyyyyyyy more resistance.
The only way to have no resistance in an AC compressor would be to re route the drive belt (if possible) so its not turning at all and theres no friction or heat or resistance.
A mechanical device such as a compressor or a shaft rotating on bearings is NOT 100" perfect or 100% efficient. The energy you put in is the energy out (that's conservation of energy, you cant create or destroy, only change its from). HOWEVER the say HP (basically Torque X RPM) you put into a gear reduction drive is more then the HP you get out, because some of the energy you put in was wasted as friction heat loss in the bearings. Energy in HP in = energy in HP out PLUS heat energy.
John T Electrical NOT a Mechanical Engineer but still picked up a few fun mechanical tidbits in physics classes, albeit nearly 50 years ago grrrr