This is because gods in that universe derive power directly from the number of people woeshipping them, right? So, yeah, the goddess of farmers makes sense as one of the most powerful, because there are a ton of farmers out there.
I’m not particularly familiar with the FR pantheon, but I would imagine a god/dess of death would prove quite powerful, particularly if people don’t just pray to them during a funeral rite, but also as an homage to deceased ancestors. Also, a deity of trade (which I’m pretty sure FR has—is it Waukeen?), as trade is very important and there are doubtless plenty of merchants and trade guilds.