When Naruto created the clone that Sakura had more chakra than, he had zero other clones at the time. That'd mean the clone held 50% of his chakra, therefore Sakura has more chakra than 50% of RSM Naruto. Taking this further, Obito made it clear that the clone didn't have enough to open a single portal. Sakura opened over 3, therefore Sakura has more chakra than 1.5 RSM Narutos.