Hi M long time no see

Torque is torque and the pdf states that motors are supplying the torque so the diameter of the pulleys does not matter.

If the supplied force is from a motor over there to a flywheel over here,, then torque is torque, and so the radians rotated and the Nm of torque when multiplied together will be the same.

So if you have 1m and 4N for one the other could be 4m and 1N,, they both are the same Nm of torque and would then take the same amount of time to change the RPM the same amount.

Total work is the same but if you wish to have it done over different times then you can change the relationships so that one motor turns more times than the other but with less force per turn or Nm of torque.

There are 2pi radians per revolution (360 degrees) and 1Nm for 1 radian of rotation is 1J