Hi there,
For Pakistan get a PCC made from 18 years till date based on your permanent address. That is because for any police records the system is designed to link it with your CNIC and police station of the permanent address. So if during all this time you had a single permanent address, then just make 1 PCC covering 18 years till date for that one address.
The overlap doesn't really matter. The PCC doesn't really show that you were living in Karachi during that time. It shows that you have no police record during that time. Since your permanent address has been there even while living abroad, it makes sense to furnish that record.
Secondly, providing more information (for example overlapping dates) is not a problem, it is when you miss out any dates, even a single day, that your PCC gets rejected.
Does that answer your question?
P.S. I am a citizen now and visiting Karachi. Answering your question while sitting awake at night due to jet lag