Intention
What a lot of people, even within Konoha, did not know was that the original intention of their so-called 'Rookie Nine' was an elite, small-scale army capable of the utter annihilation of any enemy of Konoha.
It had not originally been the intention of the council who had created the teams and assigned them, but rather an idea which had developed halfway through, after the squad known as Team 8 had been decided upon by the council. Following this the council had adjourned for lunch, leaving their assistants to file their paperwork for them.
When they reconvened, they discovered that Team's 8 and 10 (9 having been formed the previous year and left under the tutelage of Might Guy) had been filed next to one another. One member of the council had noted the probability that those two team's would likely end up working closely together as Tactical and Espionage units. This had of course led to another council member wondering who would be the muscle needed to back them up in the event of actual warfare.
And so had begun the review of all the other genin candidates for the formation of the 'Muscle' as they were known at this point. This had led to Uzumaki Naruto and Uchiha Sasuke being dragged from the standard Medic, Fighter, Strategist, teams they had been assigned to. Of course this had resulted in the question of the third team mate.
Eventually one had proposed that Haruno Sakura would be a good choice, purely because something about the girl reminded them of Tsunade in her younger years.
And so it was decided that Teams 7, 8 and 10 led by Hatake Kakashi, Yuhi Kurenai and Sarutobi Asuma would form the 'War Unit'. Of course all of this planning would fail with Uchiha Sasuke's defection and the breakup of the rest of Team 7 to train under the Legendary Sannin (This would cause the council to agree to never attempt this sort of planning again.)
Years later the council member who suggested Sakura would stand by the gates of Konoha watching as Uzumaki Naruto led the rest of the 'War Unit' off to fight the current threat to the village, realising that maybe their planning had been successful, just in a rather roundabout kind of way.