First be thankful that the dog can find and flush birds.This is the first and most important quality of a good hunting dog.Now you want him to like hunting with you.
Usually the better their nose is, the harder to keep them in check hunting close because when they go in they already know there is that bird there. Training them to be close while walking on the field can help but you have to give them freedom to follow that scent also.
One of my best flushing dog who is 16 yrs old and still hunts used to flush grouse way far off while I ride the ATV.It took a lot of planted game and shooting at the ones next to me even when the dog was not there, that it dawned to my dog that being close to the shot(which is me) is where it counts, not just flushing.Somehow you have to make your dog like to hunt with you but you don't want him watching all your moves and depending on you all the time.One thing that worked for me, whenever you hunt game planted by you for training, start the dog away from the game and if he takes off, go to where the game is planted and call, as soon as he is close enough try to flush the game yourself and shoot it for him. This association reinforces the hunting together as a pack and works for most dogs, but unfortunately not all.Some are so independent having very good nose that your best recourse is to have good legs to catch up to them.They bred them that way for years to compete in field trials.
Anyway I hope some of this helps.
louie