Naval Units at Close Range

[K K Rossokolski]

That suggests that 100 % of shells were skimmers, which I doubt. Remember the atolls such as Tarawa are low, flat, and sandy. Very little to stop a low trajectory shell. A rougher landscape would trap most shells . It is a reasonable point, but not IMO of any great importance. The term "larger" is imprecise, presumably meaning ships larger than destroyers.
Naval guns of this era were designed for long range firing against moving targets. Heavy calibre weapons were essentially antisurface. Ranges/bearings were derived from visual, later radar information, adjusted by spotting FOS. Naval gunfire against shore targets became increasingly important, especially in the Pacific, used mostly against area rather than point targets. Larger units would be well offshore. Sailors like searoom.
The chances of taking out a bunker or pillpox with a "direct fire" shot would be very small indeed.

Don't overestimate the effect of the German glide bombs. They were active in the Med around the time of the German surrender, but while spectacularly effective on a few occasions had little overall effect. The guiding aircraft was very vulnerable to AA and fighters.
Most effective aerial guided weapon of the War was the Kamikaze.

Excuse the broad nature of this response..I am away from home and thus my library, currently with very little computer access