According to your interpretation of the setting, you mean.
After all, humans working with non-humans happens ALL THE TIME in the setting. The Scarlet Brotherhood does work with humanoids frequently, albeit in a master/slave capacity usually.

The settings of Sasserine and Cauldron are both very cosmopolitan, with non-humans and humans running around together pretty commonly. GoS has humans working side by side with hobgoblins in the first adventure, as well as the smugglers being perfectly willing to sell weapons to lizard folk, who are written up as not particularly hostile to the humans that live, what half a days walk away. A day maybe? Oh, and let's not forget that the whole point of the next two modules is for the humans of Saltmarsh to team up with said lizard folk, as well as a handful of other races, in order to repel the sahuagin threat.
I'm really not sure where you are getting this xenophobic thing from the setting. Virtually none of the setting materials actually reflect this. Most of them, including the art, depict strongly mixed, cosmopolitan populations that probably wouldn't bet much of an eye at something like a dragonborn or a tiefling. Heck, THIS is the Tiefling that the back country folks of Saltmarsh deal with routinely and don't have too many problems with:
Not really going to pass for human in any kind of light.