It's been a long time since I have read Crows, but from what I understand, Bouya Harumichi pretty much did the exact same thing as Hana Tsukishima, and arguably even better than Hana.
Hana's team lost to Manji and Hana lost to the strongest Manji guy, Bisuko. Whereas Bouya was able to defeat his Manji counterpart. Sure, Bouya was sort of the lone wolf at Suzuran, but when push came to shove, he was able to rally the entire school to follow him. I'm just kind of confused why despite his legendary status, Bouya wasn't given credit for also uniting Suzuran.