Ron Kirby has done a good bit of work too.
Let's analyse a little further. Ireland is effectively divided in to links land on some coasts and a whole lot of heavy, farming, green and gently rolling countryside elsewhere (with some lakes and hills and glens but still the same type of soil with the same kind of drizzly weather).
The only links courses built by Americans are Ballybunion New by RTJ, an awkward site with a course that was very bold but that his own team felt was a missed opportunity... and Tralee, built by Palmer prior to the minimalist / second golden age movement. Tralee is extremely well thought of if not quite to the tastes of the general GCA crowd. We'll come back to the sea in a moment.
All other courses were built on heavy soil. Some had the advantage of being built in beautiful country house estates but again, most were built in the 90's at the tail end of the more American target golf / containment mounding era of golf design and before the minimalist movement kicked off. Given the nature of the entire Irish midlands, if Tom Doak was to build on that kind of land today, I'd imagine we might get a style of course more in keeping with his new one at St. Emilion (which looks great to me if a little more "normal" and less flashy than some of the sand based ones - maybe a good thing).
The Americans that did build on that land tended to be the ex-pro big sigs (because everyone was wooed by the money, ego and name in the Celtic Tiger 90's) and because of their size, they tended to be the slowest to jump on the latest trend (i.e. a more natural look). Doesn't make the courses bad. Just means they don't fit the taste of this forum and there was nothing innovative or new about them to the larger golfing world. Jeff Howes did do some excellent work on more modest budgets. Jeff initially worked for RTJ and Nicklaus as well so his style is not too dissimilar.
Back to the sea - No American has built on links land since the masses started to trend back towards a love of more natural, lay of the land designs. We almost got the 36 Doak / C&C facility at Kilshannig. We might yet get Inch. We did get a Fazio renovation of Waterville that was very well received but let's face it, because of the nature of the job, Fazio was always going to build his green sites rather than find them.
If an American does get a links site - no matter who that American is - the big question for me is whether he can resist from over-cooking it. Our modern architects are so skilled and sand is such a play-box, that it is all too easy to add in too many features. Real classic links course were actually very simple affairs - subtle and simple. A modern course could very well end up great - of the highest echelon - without actually resembling an old style links, being clearly modern rather than timeless. That's not necessarily a bad thing. It's just something I keep an eye on.