The forces you need in a pitch are much different than a full swing. You want to sense an even amount of pressure away and back through the ball, which will prevent you from overaccelerating.
By applying the same amount of pressure down as you did back, you have the aid of gravity going down through the ball. Issues arise when people start to apply too much pressure in the downswing.
Using that two-to-one backswing-to-downswing speed ratio, you’ll find that you’re creating crisp, ball-first contact that will result in consistent and controlled pitch shots.