11339.8Kg is the force rating for the actuator itself. Just to inform you I don't own the actuator and am in no position to buy it I was browsing to see what kind of force would be available. In terms of the attack I would use a fast actuator to be able to fully close in 15 Seconds +/-. In battle I would only open the grabber wide enough to just get over one point so I am then able to quickly make a tight seal on the robot. To get under flippers I would most often go side on and I will place a thin metal sheet to make contact to the ground. To Prevent this sheet catching I would then place large steel brackets to allow some rotation/movement of the plate. The Low profile of the front panel works well at bringing the opponent right up into my jaw.

You can see that the second after a flipper has "Flipped" there is a large area of exposed chassis and in some cases the plate to get under other robots is attached to the flipper therefore I can use this point to gain access with my jaw.

Please not that not every Robot is the same so people may have made systems to combat these.