@AdorableSaucerPerhaps marking out some Oases or the like where settlements would be located, not to tell you what to do, just thinking about possibilities. Then again, having the deserts be the strategic equivalent of an ocean is interesting too (which they are in real life, basically, so there's that). Very hard to cross. Maybe a better way to put it is to incentivize crossing in order to interact with the other factions in the north, not to presume you haven't or I know that's the best thing to do. Actually, from the description of the sludgelands, that sounds like something that might happen. If sludgelands are really so full of valuable artifacts, then that's a potent strategic interest for the KH and the OT. Most sludgelands are located in the middle of the landmass it seems, except for those to the west. Otherwise don't know what reason the northern coast and inland would have to interreact with each other. Maybe some agricultural product— wine, like Clocktower said, or this world's post-apocalyptic equivalent of opium/heroin that can only be grown in the desert or something— I'm not really sure if something like that exists.
Maybe those desert-dwellers want to move out of the desert, but there's no other factions in the south, so moving into the north with the costal factions contesting you isn't very viable, relatively. The possibilities are interesting, can't wait to see what happens
*Just speculation, I'm not necessarily asking for a response— better to find out in the RP for the sake of preventing metagaming. Think the discussion is interesting, still
Protective gear is also an interesting matter. I doubt gear meant to fit humans will fit ratkin, and same for ogres. They will have to adapt that technology if they find it in the ruins. The MDR and NJ meanwhile are in close proximity to/in ruins that have such gear, and it already is made for them. Wonder if NJ will ever find the sludgelands to the west. Not sure they'd know what they'd found though