This thread reminded me of a phrase Sub Zero said in the latest Mortal Kombat game.
"You and your friends show much promise, Cassandra Cage, but until you function as one, you will fall short."
Learn to communicate with your guild in the spar room and you will fight cohesively. Practice sparring while Skype calling your teammates. You will naturally end up working as one: gang up on cornered members following a 1 second order, fall back in an instant, protect your lower health members when he calls for distress.
Your team might not have perfect sparrers or come close to winning, yet you will function as one and fight much better.