Carbons Relationship to Payback
OK, so after looking into things, it sounds like Payback takes A LOT of cues from Carbon. now the 2 worlds are not connected in any way. but there are some things that are coming from carbon. let's start.
in Carbon, the goal of the game was to build your own crew and take control from Darius who controls the city, the cops, and the crews in much the same way the house does Silver Rock City the reason I say Darius controlled all of those things was because one of the first cutscenes where he says "I don't remember asking for your help crock, what makes you think you can bounty hunt in Silverton without my approval" and "near the end of the game he gets the leaders of each of the crews you took out to join his crew after all of the people from his crew decided to join your crew") now, i don't think that's just a coincidence (/s "I think Darius always had some control over the crews in the city apart from yours and the Scorpion crew") and Payback seems to have the same goal as carbon, you need to build up a crew and get revenge against the major crew "The House", in fact they made that a point during E3 that you needed to build your crew and get revenge against The House.
now, what about the name Silverton, Silverton is the northern district of Palmont City. In Payback, we have no clue of the naming of districts or if there even is any, however, the name of the city in payback is Silver Rock City, but the similarities do not stop there. Silver Rock City, is based on real life Las Vegas, Silverton, the Northern District of Palmont is also based on real life Las Vegas. I really don't think that's just a coincidence there are too many similarities there for it to be a coincidence I mean both have the word "silver" in the name and both are based on the same exact city. I think Ghost Games is really trying to tell us "hey these games have more in common than you might think and we are actually drawing inspiration from carbon for this game"
but, there is more, in paybacks reveal article they seemed to make a pretty big point about "deadly drops in Silver Canyon". the only other NFS game to have "deadly canyon drops" was NFS Carbon (and maybe world, but I don't know I just assume because world was just old NFS maps merged together) this could be possibly pointing to canyon duels/battles returning, if you want to read more on that theory I have another Reddit thread dedicated to just that.
so far those are all things that make me think Ghost Games is using it for inspiration. if you have any more similarities please post them down below.
Darius's crew (the antagonizing crew of Carbon) name is "The Stacked Deck" the name of the antagonizing crew in Payback is "The House" both names are references to gambling and both names are references to Poker/other gambling games that use cards.
the name of the western district in Palmont City (Carbons City) is Fortuna the name of the state in which Payback takes place is Fortune Valley.