The only villains if they won could affect on a large scale is Scar and Mag- the rest mostly affect their heroes, which looks like quite a big thing because they are protagonists.
And the way mag deal with rebels is just to get rid of their wishes, which is definitely not brutal if you think about what scar did to mufasa to be king.
Maleficent
Ursula
Jafar
Scar
Hades
King Magnifico
