It doesn't matter who or what, communication is always useful. So many problems result from poor communication or misunderstandings.
I've always felt, for good overall medical care (and I include dentists, chiropractors, psychologists etc in here too) that you need a gppd GP, someone you really get on with well, as the spider in the centre of your web. HE (or she) communicates with all the others, so anything you're told by a specialist, the GP has a handle on it as well and can help reinforce. It also helps prevent sometimes conflicting instructions or medications.
You can have not-great specialists, but a not-great GP is a disaster. A not-great specialist with a great GP - you'll do OK, your GP will refer you on if it's felt to be necessary. But the best specialists in the world, with a rotten GP - you're in trouble, because unless YOU step in and take detailed notes and communicate effectively with each one, they're still not going to be able to communicate with each other except through you. Not good.
And if you have specialists who talk to each other directly - great! If, for any reason, you don't get on with either of them or feel they're missing your needs, you can always move on from one or both. But good communication rarely leads to misunderstandings.
I wish more specialists would talk to each other about their mutual patients. it would save so much time and energy.
Marg