Just a though. Ryanair de-camping (albeit) slowly from DUB and Ireland in general could be a pre-curser to the next take over of Aer Lingus.
The Irish goverment/EU arguement that Ryanair would be a monopoly airline in Ireland if they purchase Aer Lingus would be rather weak when/if Aer Lingus themselves have become the monopoly airline.
A third take over attempt, if successful, would then only require the disposal of the A320s with B737s in Aer Lingus colours. (For a time?) And the problems of duplication over routes would have been sorted pre-take over.