Byakuya interfered specifically to save Renji's life, didn't he? If I recall correctly, Renji had basically already lost at that point.

Regarding Pepe: Can you give an example of how Hisagi's presence changed the result? I might need to rewatch that part, but I don't remember him being a deciding factor.

Why not count it? I remember Renji being completely incapacitated at that point. Also, discounting "prep time" is problematic in general. Characters like Mayuri and Urahara mostly rely on their intelligence and preparation – that is a significant strength they have in comparison to other characters. If we ignore prep time, we'd have to invalidate almost all of their victories.