The amount your stance is opened is dictated by how you set the club face, as you set the shaft in line with your front arm. You can then use this template to align the club face behind the ball at your target. This will automatically align your shoulders and THEN, just allow your feet to comfortably setup under your shoulders. I know this is a lot of words to describe how, but with a little practice it will become automatic. If the club face was a little “open” when you took your grip… your stance will end up a little opened. And with a “closed” club face, your stance may look more square of even closed to the target line. In general with a correct setup your stance will be a bit open to the target line. This will allow for a better “view” of the target and to rotate to your finish.
NOW, you should never feel it difficult to rotate through to a finished balance. If you are… you may be, not setting enough weight forward to start… or shifting your weight towards your back foot on the backswing, then getting “stuck” with more weight on the back foot. Even with a “closed” stance, you should not have trouble finishing your rotation.