I dunno. I live in washington state, in a county, a city, a fire district, a public utility district, a library district, a park district, a school district, a transportation district, and probably one or two other things. Some of them share borders with the city, but not all of them, and my city happens to be an island which makes sharing borders easy.

There's lots of reasons to separate municipal agencies, even if they cover the same geography, so it doesn't surpise me that each canton has about 100 municpal agencies.