They'll just devise a new system. Most of the time, the keepers memorise which penalty takers have habits. Stockers has said before, Roberts insists on them watching videos. He only mentioned it this time, because he was expecting a couple of other Brentford players could be taking it.
It's no surprise that Stockdale is as good as he is with Ben as GK coach. He makes the keepers do their homework on strikers, as well as putting them through vigorous warming up exercises, making them dive one way and then the other. It's one of the things I love to watch when I get to a stadium...