In part, it is also because he's gotten so good, nothing can really challenge him, and he wants his band to be the ones doing the fights, so they get to have that experience. Still, all the same, they are no slouches themselves, and thanks to intimate experience, can keep up with him for the most part, just...not quite at the same level he is.
So, a scale was developed for power levels: If you take only Juggler's single attack to defeat, you're a weakling. (Keep in mind, Juggler's single attack was one of the strongest attacks in existence near the beginning.) Take the twin dragons? Congratulations, you're a goon. Take the three prongs? Elite mook. Spin cycle? Graduate into individual fighter. Take 5? A strong fighter. If it takes the sever slash, you're one of the strongest current warriors in the world. Seven sins is reserved for the strongest warriors of all time. 8 elements was used once, and only once, on a literal GOD.
So, the sixth member of Juggler's band, based on a broken rubber band, was one of (if not being THE) the first to experience the sever slash. The seventh member, based on a rusted paper clip, was similar for seven sins. But they later gain an eighth member (a LARGE black hairpin), because he does the impossible: he took an 8 elements attack and kept fighting after taking a direct hit.
As the twin rider is apt to point out, "We don't have a ranking for surviving the 8 elements." The guy still lost the fight, but it came down to a battle of swordsmanship, skill, and sheer willpower, one Juggler only won because of prior exposure to poisons and to the basic methodology of the weapon in play. And it was by 15 or so seconds only.
But that was it.