Personally, I think a few ligher, but still armored gun emplacments would help out a lot. Say, if there were '88s, 105's, 120mm's, or whatever they used in concrete block houses, that would be a big help.
CV couldn't draw too close, LVT's could get on base, and the gun is too small with too restricted an arc of fire for much. But they coudn't strafe them down in a reasonable ammount of time either.