Let's say a section in a project has sequential review and then 'Submit for Review' is clicked. Now the first user has to complete their part of the review. They can do review at the question level. But at the section level if they have to complete the review, they will see a 'Complete Review' button.
This can be misleading to the first reviewer, especially if he is an admin. He might feel that if he clicks this button, the section will be fully reviewed and closed.
So, for sequential review, the button should be called something like 'Complete partial review'. Only when the last reviewed is reached, the button can be called 'Complete Review'.