Broadly speaking there is only one agency that is the ISI, there have been brief periods where it’s dominance has been challenged but its never lost its dominance. The key moment for the ISI was post 1979 invasion of Afghanistan..it was empowered in terms of money, training and equipment and given the strategic depth with an Islamic twist ideology. After that the rest as they say is history..I vaguely remember a figure (can’t remember the exact quote) that there are approximately 2 ISI officers for every district in Pakistan.
The agencies did have a role before 1979, Ayub Khans election, the creation of the republican party, trying to manipulate the 1970 election and so on. .but in those days the civil service was still immensely powerful so there role wasn’t as pronoinced.
You do not have any Idea what you are talking about i guess your main source of information is that biased media who blame ISI for every mishap on the planet
Just for your info, ISI was created after 1972, there was no ISI prior to that…