In other words, without the Mustang hurting them at 25% per month, LF Reich is very healthy on D-Day and positioned to add 400+ day fighters to LF 3 on D-Day.
LF Reich actually transfered around 800 fighters to LF 3. Granted allied deception plans meant the transfer didn't begin until 7 June, and the tremendous damage done to airfields in France meant the operation actually took a few days to complete, but the forces were transfered.