I just think it's kinda fucked up that Hojo gets almost no mention from Kotarou, if any.
Hojo is also my favorite sengoku clan so there is that
Also Hojo wasn't Oda's vassal. They were allied at times but Hojo was the last clan to go against Oda's spiritual successor in Hideyoshi.
Their defeat signifies the end of the actual Sengoku period