"Looking good" and in "Capable condition" are two different things. Getting a dog to perform at its optimum weight and ability can be a science in its own. Seen dogs look the part, but blow hot very quickly.
"When i get my SBT in what i call ' Good shape ' she looks great ( Imo ) but doesn't perform at her best" - case in hand.
Horses for courses , i wouldn't have a lab to run bunnies, use the right tools for the job in hand. Not saying your staffords are wrong for the job, but only expect the best from their limited capabilities in their not so chosen field.
Dont over cook your do