I think a Fortec 1.2 meter dish weighs less than any other 1.2 meter dish that is available in North America.
The capacity of a dish motor should be expressed in dish weight the motor is able to move, and about the only one that has a weight rating is Stab.
Originally, Sadoun had a weight rating for the DG380 that was about equal to the StabHH120. He had to change the weight rating several times and finally settled on a weight for the DG380 that was equal to the Fortec 1.2 meter dish he sold. You exceeded the advertised weight limit for the DG380 when you added a lnb to the dish.

Motors work better in warm climates. They have to work harder in extreme heat and extreme cold. You also have to figure in the extra weight of ice or snow in cold climates. My DG380 has worked pretty well moving a 1.2 meter dish, but it has gotten stuck a few times at the lower end and needed some extral help to get moving again.

I ran a Stab HH120 for many years and it still works, albeit very slowly. The Stab HH120 will not travel quite as far in either direction as the DG380, but it never has gotten stuck and would not move like the DG380. The Stab has a deeper gear reduction which is great for moving weight but it causes you to wait a while for the Stab to move from one end of the arc to the other. IMO, a Stab HH120 is the best for a 1.2 meter dish.

Volts X Amps = Power in watts. This means Ku motors can only draw a few watts of power form the fta receiver.
Motors such as the SG6100 show some impressive specs but in reality they can only draw the same amount of power in watts as a Stab. The SG6100 moves faster than the Stab which means it cannot carry the same amount of weight as the Stab. We will be struck with the slower Ku motors if we want to move 1.2 meter dish weight until the Ku motors are somehow improved or until the fta receivers are able to supply a lot more current to the motor. EB