Vegeta is mostly unable to keep up with Goku. It's only when he's put at a large distance that he's able to mount an offense, but even that is quickly dismissed and he's owned again. He's just about out of his mind after Goku's done facefucking him.
Goku vs. #19 is very similar with Goku disappearing and reappearing behind #19. He outright stops a charging #19 with one hand, albeit with noticeable effort. #19 is getting demolished easily; he gets back up after the assault simply because he doesn't feel pain.
I mean, they could very well be similar gaps, but one could just as easily be a larger gap and it wouldn't contradict anything because both opponents were owned with incredible lack of effort.
Huh, I wonder about the gap between Vegeta and #19 now. It's gotta be a lot considering Vegeta's energy loss, but still...
Rereading the #19 fight, why the fuck was Gero so surprised after Goku's first attack? It was a fucking elbow that knocked clown boy half a mile away. Was Gero assuming #19 was already strong enough to own Super Saiyan Goku? I mean, it makes sense with what he says about Goku not being a threat even after transforming, but I always chalked that up to him hoping for some degree of absorption (which he hints at later when he says #19 would die before stealing any power). All throughout the fight, he's looking shocked or making concerned comments about his robotic slave being beaten so badly. It makes me really question how valid his power comments truly are now honestly. He initially says #19 is capable of beating Goku, then later on says Goku's power greatly exceeds his data...like, what the fuck, could you not make contradictory statements, bro? I guess it could be "standing ki vs. fighting ki" but even then, to make such a giant miscalculation is kind of baffling.