Its really tough though - short yardage in GLB never seems to get stopped because of d-line surge, it always seems to be because a defender gets penetration at a spot where they can make the tackle. Its all luck really, but yeah, you need the right scheme, which is goalline with a blitz.
Converting on 3rd/4th and short is unrealistically easy in this game. You can blitz 3 LBs and a safety through the middle, but you'll get smoked if they throw.
I was able to successfully stop some plays at our goalline running a goalline formation, Cover 0, Man to Man, short, stack the box, strong side shift, blitz MLB 100%, CB2 100% against a goalline pass and a few runs but if they run a Power I or a strong I it is really hard to stop.