Like all other applicants, they will definitely see how rigorous your courseload is. Since the admission counselors specialize on a specific region, they will be used to seeing applications from your school+area and will have seen the courseloads and grades of other studnets from your school/area over many years. So they don't really need a ranking to know how you compare to other students in your school/area who are in the same year as you.
In short, they will know how you stack up to others by seeing your GPA the same as they would if you had a ranking. IMO, there's no difference in acceptance chances whether you have a ranking or not.