Of course it goes without saying that overstaffing at Aerlingus was not confined to Shannon. However the changes in work practices that occured in Dublin and Cork earlier in this decade do not seemed to have been extended to Shannon.
400 employees does seem very high for the size of the operation there. Cork has 4 based A320's and gets by on a fraction of that amount. A similar imbalance exists in the numbers employed by Aer Rianta/SAA. ( 3 times the number at Cork with similar levels of traffic).
Any fair minded person will agree that the cost base at Shannon is very high for an airport of its size.