Spoiler: show
since current balance means you should promote them for subs it means you shouldn't be able to ground-fire them.
i can't exactly tell form that pic but to me it looks like you could make that hill lower and it will be fine - underwater decals also add a lot of texture to the sea floor so you could use some thing like those to mark out mexes as well there was some crazy blodirmap with large pond in the middle and decals all over it - could look at that
hope this helps