The Praetorian Guard appointed Claudius as emperor, and had assassinated several others, all of which could be considered, arguably, a major step in the downfall of the Roman Empire.

Remember, this was a response to illustrate: ”When your military suppliers and contractors become large enough to buy the government, they grow like a malignancy, bleed the productivity and resources of the empire into building things that explode, and kill the host."

Not just Claudius, they were involved in a few imperial transitions.

But it's debatable if that's a military-industrial complex functioning in conditions of economic hazard. Like, advisors and royal courts plotting against the ruler is fairly common and historically never involved stock buyback schemes.