Air New Zealand Link will be ONE airline operating a big fleet of different sized Bombardier props and a number of 1900's.
Not a bad idea...except that Air NZ has purchased the ATRs off lease which means they're commited to them for a while (years) yet. If you wanted to dump a fleet, it would be smarter to keep them on lease and then just not renew it. Selling/disposing of aircraft is much harder.
Besides, the Q300 is now middle-aged technology with the production line being wound up and the Q400 still has teething problems.
If Bombardier would hurry up and sort out the Q400, then get the shortened Q400 up and running as the Q300 replacement, we'd have ideal machines for NZ.