I know we all admire Jiraiya for his students...4th,the hidden mist kids and naruto. The 2nd 3rd and 4th all had great disciples even tsunade but Oro has literally harbored atleast 3 HIGH jonin(taka) -Mid level kage and 1 above kage leve(sasuke)and im not saying that they are the greatest students but they were the most unlikely to be so strong. That being said if Orochimaru invaded later would he have succeded?