How would the structure change, apart from condensing the bases into AA,WN and CH?
Possibly with the CEO's comments that he would like an all ATR turboprop fleet? Only one operator of those in the group?
An all ATR (42 & 72) fleet certainly has its advantages but on the other hand, why is there a mixed (Boeing & Airbus) jet fleet? Also I think Air Nelson and Mount Cook should be merged into something 'new'. Seniority lists are more a political matter than a technical issue which could prevent such a merger.
Closing down all regional bases and leaving only AA, WN and CH would make a long-term career as regional pilot a lot less attractive i.e. very hard to afford.