The humans...

>swampdesert

How does that work, exactly? I'm fairly certain those two biomes are complete opposites.

make a rat civilization instead

make them extremely be social, empathetic clean freaks, because actual rats are

Last I checked, and I could be completely fucking wrong, a number of Deserts have Swamps on their outskirts

>the orcs, bemoaning their lack of intimidating lands and architecture, invade the human lands en masse
>the green muscley orcs from over yonder have faced a dire shortage of massive tusks for lack of deadly megafauna and their carpenters are desperately searching for an alternative