Hey Enalya,
Good stuff on Saruman! You can tell it is him regardless of the text.
There are some parts where I think you can improve on it by minimal effort.
1 - The shape of the nose feels a bit off. The tip seems to bend down while the ref I found looks to be more straight.
2 - The frown folds between the brows could be a bit more pronounced as shown in the same ref.
3 - His upper lip disappears behind the moustache and his lower lip seems to protrude a bit more.
4 - the shape of his forehead seems to round off a bit more at the top.
Hopefully this helps:)