Iranian missiles are in larger quantity which is needed cuz they dont have anyother option. Pak has a lot of other options against its enemies rather then just missiles .
Iranian strategy was to develop large quantity of suitable range missiles that could reach israeli homeland , thus the large numbers of MRBM like emad , ghadar , Kheyber shikan and the newer Fatah .
While Our strategy was establishing deterrence with our main enemy India , Developing a launch vehicle with capability of launching a payload of a ton in weight or more was imp. And with that we increased range and the capabilities .
Nuclear armed countries build missiles regarding to their warhead quantity and designate such class of missiles separately from conventional ones (reason of us building ARFC) .
For people wondering , why doesn't Ranges of our missiles are being increased , It is because we need to look at who are we pointing at , The European countries still think of us as a Nuclear armed Afghanistan and they wont take long before sanctioning our missile program further , or just ploy with the zios to destabilize us further .