McArthur has higher damage scaling to lower hp scaling than Nobunaga, so I believe if you had a lvl 20 McArthur and a Nobunaga they'd both be riding around in tanks with the +3 range but McArthur will dish out higher damage while being made paper, worse than Nobunaga atleast. While Joan ofcourse has the highest hp scaling to the lowest damage scaling, then Alexander, then Cleopatra. Napolean does Alexander damage at +5 range. Not sure about Churchill.