An air force is a fighting unit. The USA especially had the resources to transfer its best pilots into instructor roles. This improved the effectiveness of all pilots in the force. While the very best LW pilots were possibly better than the pilots they were up against there were no easy kills, by contrast the new pilots in the LW were no were near the level of new pilots in the USAAF. In the Pacific things were even worse, Japans best pilots were in service, losing a carrier not only lost a ship and a lot of planes but also the elite of their pilots which couldn't be replaced.