Man orichimaru have tonnes of ninjutsu more than u know. Everyone knows that he is the master when it comes to forbidden jutsu he has been studying it for more than 35years trust me even if jiraiya can defeat orichimaru it wont be easy for him cause when we saw a semi healthy oro fight naruto he stood his ground dont underestimate himOf course Jiriaya is stronger than orochimaru, before when orochimaru was leaving the village he was stronger but jiriaya wasn't trying to kill him either and gave up on trying to save him after. Itachi even stated that if he and kisame fought jiriaya that all of them would die and that's saying alot. In case someone says Itachi was really good and didn't want to kill one of the leafs strongest ninja because he cares about the leaf are wrong. Itachi may have been under cover but he has to do what the he was told to do collect tailed beasts and we all know from kissme that he and Itachi never trusted each other from the moment they were paired up and if kisame suspected anything he would of told pain and the others. They still do give a report to the others like kukuza and his partner was doing. I'm not saying orochimaru is weak at all, in fact in every fight Itachi had with him he made sure to finish the fight fast. Jiraiya gots Ma and Pa toad to break and genjutsus (in or out of sage mode) and orochimaru doesn't have a good defense against it.