Is there any role of examination centre?

For example, I have heard from some reputable sources i.e. teachers and CSP’s that taking the exam from a rural or backward centre (Larkana, DG Khan, Sukkur, Bahawalpur, Okara etc.) can provide good marks. Because they are backward centres and usually students have not prepared up to the mark if compared with candidates from Lahore or Karachi. Examiner check copies with leniency. But in Lahore, examiner checks strictly. If a candidate preparing from Lahore appears at these centres will get more marks than at Lahore.
Thank you.