Extra Material Around Underarm of Suit

Is it ok for a suit to have a small amount of excess material near the underarm on the shoulder blade? A few of my suits have this issue, even though they otherwise fit perfectly across the shoulders, in the back, and around the waist . I'm not sure if this is needed for range of motion or suggests that the suit is too big. Finally, can a tailor fix this problem, especially given that it's so close to the armhole?

There is supposed to be extra material on the back to facilitate movement.

There are a few threads here and elsewhere devoted to "drape." This is what you're probably seeing , here.

Depends.
How close and clean do you like your jacket to fit?
If taken in, would it restrict forward movement?
It can be taken in by a tailor. The underarm on the side panel a limited amount. Some tailors take the seam in double (side and back) and this changes the shape of the armhole in a negative way. There is no outlet on the underarm and when reduced it makes the back of the armhole deeper and creates drag. You will feel a pulling of the jacket when you move. The side seam needs to be opened and the side body reduced, but nothing taken in at the top of the side body. The back shoud be reduced seperately. It is not terribly difficult to do, but should be altered properly. It takes time to do as you are opening the sleeve from the bottom of the armhole and upwards toward the shoulder. Resewing the side seams and reducing the lining.