Idea: Some spheres aren't really connected to the terrain or architecture at all, so what if some gods attached themselves to specific people or groups instead. Like the "Travelers" sphere, why would a god of travelers stay in one place? It'd make more sense if they wandered around the map, possibly disguised as an ordinary person, or if they followed a pious caravan or something.
Likewise, a god of something abstract like "Truth" wouldn't really have any particular reason to stay put, so what if they could adopt an appropriately minded individual as their "prophet" or "hero" and spread their worship/blessings that way? So we'd have sedentary gods whose strength depends on their proximity to specific map features, "trade-based" gods that randomly move around on roads and empower caravans/migrants, and "philosophy" gods that depend on the actions of special mortals to spread their teachings and gain power.
Personally, I think it'd have lots of extra story potential.
Example: Say there's this isolated human village near a river that plays host to their goddess, maybe they sacrifice fish to her every week to keep her from falling asleep in the winter and freezing the water. One day an elf comes through, seemingly talking to himself. It turns out he's the hero of a Luck/Games god, he gambles with everyone and wins himself enough favors and goods to stay for a few months. A couple villagers ask him how he does it, and he starts talking about his god. Soon enough, the whole town is listening to the elf's sermons, amazed by the gains to be made with this new religion just from donating a few coins in a gamble. By the time the elf leaves, he's rich and fat and the villagers have forgotten all about their river goddess in their attempts to replicate the hero's successes. The river freezes in the winter, they realize too late and none of their sacrifices are enough to reawaken their sleeping goddess. The hero of the god of Theft and Lies makes his way to the next town.