Note that Season 3 combines the Hongyue (Arc 3) and Northern Kingdom (Arc 4) chapters. So Season 4 would refer to Story Arc 5 (Yan Ruyu), Season 5 would refer to Story Arc 6 (Southern Kingdom), etc.
Note that Season 3 combines the Hongyue (Arc 3) and Northern Kingdom (Arc 4) chapters. So Season 4 would refer to Story Arc 5 (Yan Ruyu), Season 5 would refer to Story Arc 6 (Southern Kingdom), etc.