The Hellmaw(Legion hellmouth has been unofficially renamed by me. Live with it)So you are up against a hellmaw. Have no way to not be dragged and no way to shoot it out. What do you do? Well this is simple. Just place to models base to base in an angle that is perpendicular to the line between hellmaw and the middle of the 2 bases. As such:
Against a Legion player with a Nephilim Bolt thrower you need another jack to stand behind them both to stop one from being pushed and then the other dragged in.
Against a double Hellmaw you need to place the two set of two jacks so that if he pulls one he is hitting the other pair. Is a bit harder to do but still easy.
Easier to just stay out of range of one and then deal with the other before dealing with the second one.
People talk about Hellmaws as if they were the be all end all of competitive play. They are not. They do not work on colossals. Does not help against shooting jacks and does not do anything against cheep jacks either. So they do not really do anything. They are a cheep road block. Just the same way as all our infantry and don't get me wrong that is good but it's not Over Powered. Banshees do what 2 Hellmouths does better and at an comparable point cost.