Just for consideration and based on my assumptions and knowledge.
A LAMEless tarmac would not allow 300 to go, I think it would be far less, maybe 100? You can't just halve the terminal workforce with this model as evidenced at Virgin who still have sizeable dayshift numbers for their flights. The bigger problem is the shift of the workload from day to night.
Agreeing to this model would not garauntee job security. They would only be looking at the next project. Remember when the worforce costs x dollars a year, management are always pressured to reduce that cost further. I have just attended an Americas MRO conference and it is interesting to listen to them speak, and what a blast it was for us 9 American and 1 Australian union official mingling with 7000 airline managers and hangers on. The Engineering boss of US airways stated that his brief from the board was - your Engineering budget for the next 12 months must not be more than the previous 12 months. I was sitting there wondering how they could even cater for a CPI wage rise and the coverage for a larger fleet.