I wouldn't have gone into the detail that Easy Street did, but reflect on recent aircraft improvements and modifications and OSD.
Certainly scraping an in-service aircraft saves future costs and the cost of recent mods is simple wastage that does not affect the future bottom line.
The FA2 was upgraded and had an excellent bombing system.
The GR3 again had an upgraded system.
Now you are talking of early OSD for the GR4 or GR9 to be replaced by an immature FGR4.
What this suggests is a schism between Defence Policy and Defence Planning.