I would argue for more SMOKE - ships (including PTs, LVTs, etc) need to be able to lay smoke at the landing area. 5" WP lays a nice smoke screen during a shore bombardment. The effect of laying a big smoke layer over a wave of LVTs heading for the beach would be to lessen the icon range for aircraft in the area.
our LVT4 can lay a lot of smoke, and people do use it