The main issue of contention is one of medium term strategy outwith any alliance. That may or may not be risky, my feeling is the current strategy has brought them as far as it can.
Perhaps that is as far as they wish to go?
If Aer Lingus can finance the A350s and a presumed A32xNEO order then by the early 2020s they'll be set for another 20 years of operation; there won't be any breakthroughs in aircraft efficiency until the big two have amortized their current projects.
So if they're competitive on a direct operating basis with the rest of the industry, the current mix of long and short haul would seem to be sustainable for the future.