I don't see how they could go together. Firefly/Serenity is devoid of FTL travel or alien life, and Dune has both. The only points of similarity I see offhand are that there are psychic powers in both (a common trait of many SF universes) and that Earth has been destroyed in the Dune universe -- except that happened around 12,800 CE, whereas FF/S established that "Earth was used up" centuries before the series' timeframe of 2517 CE.
Please refresh my memory as to where you saw this information? And other than the sandworms, what alien life? There's certainly no sentient
alien life in Dune.
And if you mean the robots and cymek crap from the KJA/BH books, no serious Dune fan considers those anything more than really bad fanfic that managed to get published. It was NEVER part of Frank Herbert's vision of the Dune series.