Flying into Shannon and not playing Lahinch makes little sense to me
but then playing Old Head or Doonbeg makes little sense also (one is owned by an egomaniac narcissist -and the other is waaaay away from the others).
When you play over multiple geographical areas in a span of a few days, of course you're bound to miss something-or get snarky commenst from us GCAers.
It just looks like the itinerary is already set so it's tough to give MORE suggestions without changing airports or dropping courses.
That said, you really can't go wrong no matter what you do.
To Tom Doak's comments. I'd certainly call Waterville FAR more authentic than Doonbeg-even post Fazio-despite my best attempts to not like the redo
Eddie Hackett is pretty authentic.
If going the more authentic route ( which I do recommend) skip Doonbeg for Lahinch (or play both)
and replace Old Head with Dooks-and fly out of Shannon.
If you booted Old head you could always play both Ballybunons one day and pair Tralee with Castlegregory for a lower key 27 hole day
If your flights are set
mix and match the above advice- or follow some of the older threads on this subject