I think you will find that most, if not all cleats/bollards on vessels, are usually capable of holding the full propeller power of the vessel.
That would mean that the angular pull of a line preventing an overturn would be less force than a direct full throttle pull.
'Springing off' a quay is exactly the same sort of load, a line from say the forward cleat/bollard on the quay side of the vessel, to a bollard on the quay further back than amidships will when all the other lines are let go and the power put in forward, bring the stern out and away from the quay.
This is an action regularly carried out by most vessels.