Stuck Together

Kakashi is given team 7 because: Someone needs to watch over the Jinchuriki and protect the Uchiha bloodline; Sakura was just supposed to round out the numbers.

Of course the Hogake and council underestimated the fundamental breaks in Kakashi's psyche. His guilt complex ran rampant seeing what amounted to the reincarnation of his old team with some added features. He was going to turn his babysitting job into a crash course into becoming the best ninja he could produce, nothing was going to hurt his adorable little genin.