Bunker Breaking. Breeching the beaches help needed

[Steelwhip]

have played a few turns exploring options and trying to figure out what works...I did have the option Assault rule on..will have to turn that off in my full playthrough. And yeah...seems like tossing big stacks of troops at them is the only thing that really seems to work with the forces available, so really im focusing on the few places that are trenches and break through there.