The contract FO's are to ensure that at least someone on the flightdeck has a clue as to what the A320 is doing. As only a couple of the Captains have any Airbus experience, the regulatory scrutiny the operation would otherwise be under would be more than Jq could muddle their way through.
$10K NZ/ month for what is effectively a training Captain position is a long from market rate. If the flightdeck is frosty, it'll be because of the inverted cockpit gradient.