In my current WIP I had an idea to mix two genres. On one side of the world I have your mostly typical medieval fantasy side, where there is magic, dragons, knights, warlords, trolls, orcs, new creatures, etc. On the other side of this world, separated by a medium to large-ish ocean is another land mass. On this land mass is the remnants of the old world. Here is a wasteland created by the nuclear and magical explosions that happened during the Tear. The population here is much less, with small communities of people mostly making up this side of the world. They have to search for materials, water, and food if they cannot grow it, protect themselves from bandits and other communities called "Havens" and watch out for roaming mutilated creatures that have been twisted by nuclear and magical fallout. Without going through my whole story arc, my question is, do these mesh? Does a borderlands/fallout part of the world mesh with a LOTR/ WoT part of the world? And yes they would interact, magical bridges can be used to cross between these masses of lands, as well as ships if you make it. The medieval side of the world is protected from any of the fallout from the other side that might affect them, using a magical barrier covering their entire landmass. The other side mostly uses masks and things like you might see in Metro Exodus. To restate, can medieval and wasteland/apocalyptic generas mix?