I think SK should be investing in hundreds of short range weapons; not 60 super-fighters. Their enemy is within artillery range not 2000 miles away. NK can hit Soul with 1,000,000 artillery rounds per hour. 60 planes won’t do anything about that in time.
If the planes can even get into the air once combat begins, might it not start with an EMP over Seoul?
NK’s will be coming through the tunnels first
Their enemy is China. And they will need every one of those F-35's to face down the PLA Air Force when Chinese ground units surge down the Korean peninsula to annex North Korea (and perhaps the entire peninsula) upon Kim's eventual fall from power.