Really my characters are harder to scale to each other.
Erza Scarlet beats Hiro straight up 7/10 times. Both use versatile magic, but Erza has more power, even greater versatility and some of her armors (Flame Empress etc.) counter his elemental magic.
Toph beats Erza 9/10 times, since Toph controls metal and the basis of Erza's entire style is metal swords and armors for fighting. I didn't put it at a 10/10 because Erza does use magic armor and we don't know how that effects Toph's metal-bending but still.
Lucario beats Toph 7/10 times, as he is stronger physically and as a fighting type can smash most rocks or metal objects Toph makes plus can match Toph's seismic sense with his Aura perception.
Yang beats Lucario 7/10 times, as Yang is physically stronger and her ability to take a hit and hit back harder makes her favorable in bear fist brawls which Lucario specializes in.
Hiro beats Yang 7/10 times, cause Yang has issue with quicker opponents who can get a lot of strikes in. Which Hiro is pretty nimble given his fighting style and his versatility (And ability to fight at greater range than Yang) gives him an edge.
Just a few examples.