Re: Mazhar Kaleem- The prolific writer
Good question and the answer is definitely no.
While he did write a lot of children stories and introduced new characters series and they were highly popular as well amongst kids like Chaloosak Maloosak series et all (They were very good far better than Ishtiaq Ahmed series), he did not continue them due to shortage of time and demand for his Imran Series. As per his interview published in Family Magazine (from where i have written his wikipedia article) he is by profession a lawyer and writing Novels is his part time hobby. His a very notable lawyer in Multan High Court, once selected as his SVP. Also he is a radio talk show host as well and he does it one day a week despite insistence by Radio Listeners as he cannot spare time (His talk show has nothing to do with Imran series and he is known as Mazhar Saieen). Therefore he could only continue one thing due to time shortage and he opted Imran series.
But you are right in arguing that initially Imran series made him popular but now he is making Imran series popular as many of us have first read him and then went on to Safi.