Colonialism, imperialism, and the meaning of Ricardo's tale in Victory

Here's the story that Ricardo, the card shark, tells Schomberg, the hotelier (in Conrad's Victory) about how he and his gambling partner, "plain Mr. Jones," began their enterprises: they were hired to be aboard a small schooner as part of a team of men who were going to dig for treasure off the SA coast; as they were moored on the coast overnight, preparing to dig for the treasure in the a.m., R & J lured the captain on deck through some sort of ruse, Ricardo kept him there while Jones looted the cash box, and later they escaped on a small boat that the schooner had in tow as a launch (I guess). They hid in an inlet along the coast in a native village; when they learned that two brothers in the village were planning to kill them to steal the cashbox, Jones - whom R always describes as the essence of an English gentleman - casually shoots one of the brothers to death and the tie and bind the other bro., Pedro; when they cut him free he becomes a devoted, almost slavish servant to them. Thus begin their gambling exploits, leading finally to Schomberg's hotel. Is this just an idle tale? Or is it a metaphor for Conrad's view of colonialism and exploitation: The European treasure hunters arrive in the 3rd or new world, fight among themselves, one steals the plunder and both obliterates and enslaves the native population in order to retain control of the wealth - gold, silver, spices, whatever - of the undeveloped land. It's a version of Nostromo (the silver mine, the imperialism, the colonial uprising), of Heart of Darkness, probably many others - and a microcosm of the coastal trade and imposition of European culture and social hierarchy that we see playing out across the scope of this novel.