Kind of funny how that all works. Generally the federal statutes outweigh state statutes for jurisdiction, however, as you so aptly noted, that drug trafficking violates several separate and distinct ordinances under each system.
The driving concern for the police officer would be the statutes that are under his jurisdiction. If it is a federal officer he would file for indictment in a US District Court and if it was a State officer it would be filed in the State district criminal court.
The real advantage to this system from a law enforcement point of view, is if the state blows the case, the feds could re-indict in federal court, and vice verse.
Since the statutes are different, double jeopardy wouldn't apply and in effect, it gives law enforcement two chances to prosecute.
In this particular instance that you state, with multi-state conspiracy and organized crime, it would seem likely that this case would be investigated, indicted and tried in the federal system, so that their is no question over jurisdictional lines and what evidence is relevant and admissible in a state prosecution.
For instance if there was information obtained by legal search warrant in one state, that may not be admissible in another state and therefore the subsequent information that was obtained in the second state would be considered as fruit of the poisoned tree, and therefore, also inadmissible.