In Slavonia the balance of power in 1991-2 was that the Serb paramilitaries had the artillery units left behind by the Armija on their way out of newly independent Croatia. There was extensive shelling of the whole area. The balance of power had reversed by 1995 when Croatia had managed to build its own army, which it didn't have before.

Let's be clear about who was cleansing whom when: Serbs were driving Croats out in 1991-2 and Croats drove Serbs out in 1995. Neither of these were done by "small mobile paramilitary units" - allegedly there was heavy artillery involved in both cases.

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith