Yes. This is what most—all?—other democracies do. More realistically though, municipality level governments include surrounding rural areas. In areas with small towns and large areas of rural farmlands, the farmers and town residents have equal representation, but the farmers obviously have a bigger political influence (hopefully the municipality governments have enough representatives though that the townfolks have at least a couple of representatives).

In reality unincorporated America also includes heavily urbanized areas (more often than not poorer than the surrounding areas). Here in Seattle this includes Skyway and White Center. But even if aside from those it is pretty unacceptable that all local planning for the community of e.g. Fairwood, or even Hobart don’t have any say in their municipality level organization, instead relying on the same county council as Seattle for their local affairs (a council with only 9 representatives for a total of 2.2 million constituents).