Rob:
Thanks for the note.
I agree with Bruce to an extent ... though he doesn't know that St. Andrews Beach, your example, has bent greens and bermuda fairways. (Actually, I guess the fescue surrounds solved that problem, which wasn't even the reason we went that way.) I honestly think it's as much about different SOILS between the greens and the surrounds, as it is about different grass types.
But, while there is clearly sometimes a need to water the two areas differently, I am not sure that having a second head right up on the green is required. Until about ten years ago, superintendents were happy to have heads around the green throwing back in for that purpose. Now they want double coverage, and the irrigation designers require it ... even though the same irrigation designer INSISTS that the heads on the outside edges of the fairways water evenly throughout their coverage area.