That looks a bit like the radar solution on the French general purpose FREMM subvariant frigate. Which, if implemented, should be a fairly decent solution - cheap but still capable.
Only drawback might be if the fact the search/tracking radar is rotating means there are still dedicated illuminator arrays for the anti air missiles.
Ideally, IF the missiles are still of semi active radar guidance, the tracking radar should at least double as illuminating radar as well. Which is not really doable with a rotating array.
Of course, a better solution still would be to use a missile with self guidance. Be it radar or infrared. Then a rotating radar should be enough to act as a datalink array, to converse with the missiles. (so dedicated datalink arrays aren't needed for that)