i agree with you there.Kisame said (to Itachi) the name of one of the 7 swordsmen of the Mist fades before a Sannin (Jiraiya in this case) and that includes the strongest one = Kisame with Samehada
yes there are 7 of them and 3 of the Sannin
but Sannin also has Ma and Pa in SM and a shit load of snakes and toads and Katsuyu ... oh and Edo Tensei, if you go by numers this should be enough for the sannins and i think that much much less than all that would be needed to defeat the 7 swordsmen