The number of candidates for the second interview is generally rearranged according to the decision of the second interview school.
One possibility is that the school arranges the numbers in order according to your preliminary ranking, so the students waiting around you during the interview are usually students who have entered the second interview like your major.
One is the lottery system, where college instructors draw lots to decide the number of re-examinees, so it may be that students from your college interview before and after you, not necessarily in the same major.
These two ways mainly depend on the policies and regulations of the school you apply for, so don't worry too much. Carefully prepare for the second interview, no matter who is from the same college or the same major, don't worry!
All the above are personal opinions and are for reference only.