According to an MIT political scientist, the current clashes in Sudan are an example of failed coup-proofing, meaning that multiple centres of military power were created in order to create a [military] "balance of powers" between them, and thus dissuade either from overthrowing the supreme leader, but this strategy failed in Sudan:
One thing that a lot of autocrats do to prevent armed factions of the state from launching coups is to coup-proof, which means creating rival centers of power by creating an internal security apparatus. Sudan has a conventional army, the Sudanese Armed Forces, or saf, which is one of the belligerents now. Back in the early two-thousands, around the war in Darfur, Bashir decided to rely on janjaweed or Arab militias to engage in scorched-earth tactics and genocide. [...]
After that, he incorporated some of these janjaweed militias into an official paramilitary and into the Sudanese state, and allowed them to grow. He allowed them to enrich themselves, and engaged in and actually passed through the parliament a decree allowing the Rapid Support Forces, the successors to the janjaweed, to be on an equal institutional footing as the Army. [..] By 2017, through an act of parliament, the leader of the R.S.F. responded directly to the head of state. Bashir did this to coup-proof, to insure that if the SAF ever got too rebellious, or too powerful, he would have a counterweight. And, in fact, for some time, Bashir called Hamdan “my protector.”
Unfortunately for him, the coup happened anyway. [...] And, in October, 2021, when Burhan [head of SAF] and Hemedti no longer had shared interests—the civilian forces were out, Bashir was out—the split between them started to emerge.
Now examples of this strategy are certainly found elsewhere, e.g. Saudi Arabia also has two ground armies (and a paramilitary), with analyses suggesting such coup-proofing role[s] etc. However, this strategy seems to mostly work [at preserving the regime], rather than not, at least judging by Saudi Arabia (or even Russia, with Rosgvardia by some Western analyses.) A somewhat dated (1999) article discusses Iraq [under Saddam] and Syria as well, as examples of coup-proofing by parallel armed forces. In hindsight coup-proofing [this way] worked in Syria too, despite the civil war. And also worked in Iraq--only an external invasion removed Saddam. So, are there other [contemporary] examples where such a strategy failed, like [it seems to have] in Sudan?
