I started reading Kingdom recently and completed it in 6-7 weeks. The pacing was great, but the Zhao invasion arc, where Yotanwa fought against Zhao's army and mountain tribe was dragged a lot. I don't know how weekly readers would have felt during that time.
Killing the Quanrong King wasn't even enough since it was a Cheap shot and in a 1-1, he had no chance.
And this is coming from a Heki-fan.