"It's not solely about knowing who's stronger, but understanding how Oda likes to structure his stories. Oda tends to use his flashbacks as a way of adding more impact and weight to a particular scene. Chopper's flashback occurs as Luffy's in mid-punch, the Calgara-Noland flashback precedes Luffy's final bout with Enel and ringing the bell, and Robin's flashback is a precursor to Sogeking shooting down the flag and the "I wanna live" moment. There are others, but looking at the placement of this flashback sequence - as she's marching to fight in her preliminary bout - makes this a strong moment for her character. It would be something completely different if this flashback was placed in a later scene, but it's not. Rebecca steps into the colosseum and it's her versus nearly all of Dressrosa, but thanks to the impact added by her flashback, it's a stronger, more powerful moment and it's meant to demonstrate both her resolve and her strength as a person. This isn't going to be undercut by Rebecca suddenly being defeated by Cavendish, whose main connection to the storyline is his hatred for Luffy."
