As for the entire concept of "god(dess) of _____", i'm no anthropologist, obviously, but I suspect that's a very recent view spread from too many poorly designed & written role-playing games
Quite right, though the source is really more from Victorian era writers and such. Not that the crappy RPGs helped.
However, I don't see how I could dispute that Norse paganism, at least in the Viking Age, was a farmer's religion. Even in the sense that it was also a king's religion and a warrior's religion and a trader's religion, all of that ultimately and increasingly rested upon agriculture.
This is one of the reasons I’ve always been more interested in Icelandic traditions of polytheism. The people who moved to Iceland, though they did have some small farming, got quite a large amount of their subsistence in fishing and to a lesser extent hunting. They also had a representative government, which although not really egalitarian was still much more democratic than any European country at the time. As such, their religion reflected these facts, and vice versa.
Since we’ve veered off specifically to Norse/Germanic traditions, it probably warrants mentioning that these cultures were far from homogeneous. Their subsistence methods varied, as did the political structures and cultural traditions. Some were certainly 100% farming people; others, not so much.