These are apparently the full names of these cricket characters. Even though their names follow a similar pattern, they both fit perfectly as they are now.
What i mean is the way the whole world knows Imran Khan (emphasis on Khan). He wouldnt have been as famous if his name went around as Imran Niazi.
On the other hand Shahid Afridi wouldnt have been any better off with Shahid Khan. Its hard to think of him as Shahid Khan. Maybe the name Shahid doesnt do much justice to the name Khan. But it works wonders when put before the name Afridi.
bhaisahab you are assuming that they are famous because their names were such...wrong assumption sir...its their deeds...so if it had been Imran Niazi or even Lallu Lohar it would not have difference to his fame and popularity..
Chee its their deeds/achievements/persona that makes a specific image of that name in our mind. So whenever we hear that name the personality pops up in our mind. A Shahid Afridi could be a bus conductor in Karachi as well, but ofcourse his name will not have the same effect unless the cricketer Afridi exists.
Imran Khan Niazi or Imran Niazi would have equal effect under the shadow of Khan sahab's personality. Believe me. This is how it works. If he was famous with those names, those names would have same weight as Imran Khan today.