This hint will make any attack with the ALLIES 100% effective.

(1) Build x amount of dogs.
(2) Build half amount of soldiers (any type except Rocketeers)
(3) Build the same amount of tanks as soldiers. (any type)

Now set 2 dogs to guard a soldier and each soldier to guard a tank. Send the tanks to attack a base and they will be completely guarded. If someone attacks a soldier, the dog will tear him to bits, and if an attack on a tank is made, soldiers will take care of the problem.