I did not add overhead lights over my vanity (84") when I added three sconces between mirrors. I do have an overhead light in my shower + a chandelier type fixture over my freestanding tub (it meets code - unlike most of the ones in photos on this site - my ceiling is 11' tall over my FS tub - anything shorter won't work for a hanging light). I also have a light in my WC for my toilet area.

We added under cabinet lighting in order to avoid the need to turn on lights when using the restroom at night.

If the only lights you have are your sconces - you may want to add one in the center of that area of the room. However, since your room is only 6' wide, that may be more than you need. I'd rather have extra light if needed vs. not having enough. You should put all of your lights on dimmer switches.

I am not a lighting expert (obviously) - however, I am hoping that by posting a comment that others will see your post and add their thoughts.