Not really. With Vajda as coach Djokovic has pretty much underachieved all these years. Just 5 slams at almost 26? Not that great... It was because of the gluten-free diet that he started winning slams..
Lendl has been instrumental, that has been obvious. And it´s good for the excitement of the game that Muzza managed to get over the bump in the road. Still, I can´t help but wonder what the result would have been if Lendl had been the trainer of Djokovic instead. That would have probably been the scariest and most ruthless player-coach duo of all time.
Imagine if Lendl had been Djokovic's coach since 2006?
They probably would have discovered the gluten allergy a long time ago. What a scary combination.