IG Police is far more powerful than DG Rangers. Rangers/FC is only a paramilitary force that works in aid of Police/civil authorities. In fact, Rangers is operationally subordinate to District Magistrate/DC/DCO and police high ups while working in districts/divisions.
IG Police is also superior to DG Rangers/IG FC in rank. IG Police is normally a BPS-22 officer of PSP group equivalent to Lt.Gen of army whereas DG Rangers/IG FC is a major general.
So there is no comparison between police and rangers/FC. As far as your query about the role of FC in Balochistan is concerned, it is allegedly a subversive role which doesn't come in the official purview of FC so I don't want to comment on it. Legally too, Police is much more powerful than any paramilitary force.
IG of any province and DG FIA are different posts so there can't be any comparison between them. Both of these are indeed good posts.
Unfortunately, in our country bureaucrats/police officials are regularly intimidated by politicians so these posts seem to be less charming in practical arena. However, practically too there is no match between police and rangers/FC.

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