Rondo and Pierce are the two guys most likely to argue on the court all season. I've seen Pierce scowl at him, and Rondo bark back numerous times. This is not surprising, but again, I don't consider this a bad thing. Every team I was ever on that was any good got in intra squad arguments frequently and had players that didn't get along. Ubuntu is focusing on the task at hand regardless of the other stuff.
I was visiting a friend at the USN Academy in Annapolis and his squad was setting up for a tailgate, having gone to BC, I had about 10x tailgating experience, but before I could make a recommendation, my buddy pointed out "this academy is full of people who view themselves as alpha males, being trained to be alpha males, and worried about not being alpha males, sometimes its best to get out of the way on the small stuff." A sports team is similar in that almost every guy has to be extremely alpha just to make it - that means plenty of fights.