A good way to look at WoW BGs is comparing it to WC3 Bnet. A PUG is like the team you get when you hit the "4v4" button. You and 3 random people playing against 4 random people. Organized groups are like Arranged Team groups. They practice together, probably on Vent or TS and know how to complement each other with strategies.
There's a reason Blizzard made an AT ladder and an RT ladder.
Edit: spelling/grammar
There's a reason Blizzard made an AT ladder and an RT ladder.
Edit: spelling/grammar
"Just as individuals are born, mature, breed and die, so do societies, civilizations and governments."
Muad'Dib - Children of Dune
Muad'Dib - Children of Dune