im thinking jiraiya didnt fall for that, he is way too smart. also he may be stronger or a little beat weaker than itachi, or at the same level, but, jiraiya has a lot of advantages. he has a lot more experience and jutsus (imo), and can also summon some powerful frogs. remember he is the one who trained the 4th.
if they try to make sakura into a tsunade id be pissed, she is such a dumbass it isnt even funny, she's just a little girl obsessed with a guy who thinks she is a loser. tenten is the next tsunade.