I seriously doubt obito said sakura > naruto clonenot necessarily he could have been referring to the fact that they were split in the first place. he may have only put it like that because at the time the real single body wasnt even an option for use. also interdimensional jumping when its not your may just use up a shit load of chakra. it probably just takes a little more than half naruto's chakra because i doubt sakura's chakra is anywhere near half of naruto's. but then again she's constantly storing chakra so god know how much she has. but i digress. you see my point though. he never explicitly stated that the real body has more chakra. that spits in the face of years of info kishi has put downabout shadow clones.
He's basically saying he needs 100% chakra. Naruto clone can only fill up 98%, while sakura fill up remaining 2%