@ Carr: it is possible that the range given at Wikipedia is correct and that a software solution could make it possible to use the SPY-3 for something, for which it was not designed for. But on the other hand I would think that the designers of the SPY-3/4 pair had good reasons to combine radars with two different wave lengths and that usually short wave radars are not used for long range volume search. There is only one other similar radar used also for volume search: EMPAR. It it uses longer wave lengths, but was also not designed for it. It is also used alone only in much smaller ships (the Italian FREMM), in larger ships it is combined with SMART-L (S-1850M), a radar with much longer wave lengths and much more range. Also even EMPAR alone has more range than SPY-3 (based on Wikipedia). For a ship of the size and costs of the Zumwalt class, it would be a waste of possibilities to not equip it properly. If the SPY-4 is added, the Zumwalt class would be also first class air defence ships, likely way superior to the existing USN ships with inferior radars (SPY-1).
For bombarding land targets usually nobody designs expensive ships. For this purpose old, outdated ships (e.g. old battleships) or converted landing crafts were used, e.g. such ships:
https://commons.wikimedia.org/wiki/File:LSMR-513-1.jpgThese were cheap. And such ships could be rapidly built also today and equipped with cheaper missiles (e.g. something similar, but more evolved than the army's M270 launcher). But to built ships as expensive as the Zumwalt class exclusively for such a purpose, would be really a massive waste of resources.