Gyou'Un doesn't get low diffed by Ouki. Mid diff at least, even high diff isn't that unreasonable. Still doesn't discredit my point.
Rinbukun can be given a good fight by Rokuomi (who is below Shoumou, don't even argue against it), and yet even Tou needed to take some time to slay the former.
This series doesn't suffer from typical shonen power creep syndrome. You are highly overestimating the differences in strength between these characters.
Shoumou is not close to Rinbukun in strength, from where does this Shoumou overestimation come from? He was just a strong warrior general, nothing more, all these other guys were talking about have GG adjacent hype, including Rinbukun.
Rinbukun is a Chu general, making him relative to guys like Sento Un and GenU.
Gyou’Un fought the Qin 6 in the past and was adjacent to the Heavenly Kings who themselves are GG tier.
Shoumou is just a warrior general with no hype exceeding that level, why on earth are you hyping him up to the level of these other guys?