Were the Konoha 12 teams balanced?

[Ultimateone]

naruto may have been last in the class, but dude did teach himself a joinin level ability in 1 night and then beat a chuunin. that in and of itself should have given them some idea of what he was to eventually become. although at the time he was still pretty lackluster, so i guess it makes sense at the time. they also didn't know that he would be able to eventually control kurama's chakra. although they should have looked at who his parents were, even if he may not be as naturally gifted as his father, or have kushina's special chakra he is still their son. putting 2 people from prominent and powerful clans on one team is kind of overpowering a team. i guess they figured sakura would balance the scales. although this is the same village that produced the sannin, so it would seem they need 1 OP team per generation. i mean, look at minato old team with obito and kakashi. obito would have been OP with his sharingan, and kakashi was a genius, so.