Did you take into consideration that Storm covers respond quicker to friction than Brunswick cover? That means the ball bleeds energy quicker. Secondly ball speed is the most important part of pin carry...if the ball is not hitting I'd find it extremely hard to believe its over skidding such as your teammate...btw I tend to base opinions off numerous situations not one...
So if I'm hitting the pocket and leaving plaque or flat 10 pins, I should just throw it slower? With your logic, if I do that it should work, correct? Why should anybody change balls when they have a bad reaction if ball speed would just make a bigger difference? Does it work the other way? How come when Chris Barnes keeps going through the face, he switches balls instead of just throwing it faster?
I don't understand the logic. If a ball hits carry down and doesn't finish how is that a problem with ball speed? How can you correctly assume that one of the weakest balls on the market not finishing well enough is due to the ball being too strong? Especially without knowing what/where/when/how he's bowling/bowling on?
Could it also be that he's just playing the wrong part of the lane? Would a simple 3 and 1 right make the ball carry better? Is he just playing the lanes wrong? We don't know these things.
Since he has slow ball speed, could it be possible he usually stands pretty far inside due to overhooking? If so, when he drills a weak ball, is he adjusting his feet, or standing in the same spot as a stronger ball, and expecting it to work?
These are questions we can't answer knowing as little as we know about the original posters situation, but in order to help them we must do what we can with what we know. He wanted to know what ball with a stronger backend would be helpful, and a Slingshot is not that.
Also, when he said he "switched" to a 14lb Breeze and "picked up" speed, does he mean he switched from a 15lb ball down to a 14lb ball? If so that is even more evidence that the Breeze is too weak, not too strong, as he's throwing a weaker ball than he's used to, faster than he's used to throwing it.