Ok i tried it. It was kinda interesting.
Even if i put a smaller version of the moon closer to us if it is in the same position you get the same kind of shadow.
Only when i change its position horizontally to the left it gets the same shadow like the big planet.
It makes sense when you think about it. When it is on the right side we see more of the shiny side.
When it is on the left side more from the shadow part.
So i thought if we are very very far away and zoom in (kinda orthographic view) then the shadows should nearly look the same and when i tried it it looked so actually.
It depends how close we are to the objects and in which relative position we are as it should i think.
So no change, sorry guys physics don't let me change it and i don't want to fake it