Kakashi couldn't move while facing one of the sannin (orochimaru), Kabuto went up against two of them (he only fought tsunde, but still, he made Jiraya into his personal enemy) and on the overalll count, he would've won (he beat Shinzune in three moves, he bitchslaped Tsunde into plup and he took the rasengan head on, and still had the power to be suprised).
and even though I admit that the ANBU members will never beat anyone, my argument still has a point; those 8 were stationed at Sasuke's room to protect him against Orochimaru, or at least to make sure that an alarm is raised when orochimaru gets there, Kabuto killed them all without even trying...
oh, and Orochimaru said "you most likely can't kill me, you're strong, but only about Kakashi's level", which means that if anything, Kabuto is between Kakashi and Orochimaru, according to someone who knows him good, and not from Jiraya's first imprssion.. and besides, Kabuto also scares (sort of, not exactly scares, but close enough) orochimaru, have you seen Kakashi treating Jiraya like that? Kabuto is being cynical to the stumck with Orochimaru, and even orochimaru can't read him..
Naruto, Gaara and Kabuto, the only genin team who can beat the sannin, and maybe itachi...