When I first started getting into Glorantha, it wasn't the ducks that threw me for a loop.
It was the mobile plant people. And the fact that I couldn't figure out if Dwarfs were literally made out of rock or not.
In fact, I'm still not completely sure if dwarfs are literally made of rock or not.
But the ducks? Never seemed weird or silly to me. When I first started pitching Glorantha to my adult children, all of them pretty much said the same thing
"Wait, what? Ducks? we can be ducks?! I WANT TO BE A DUCK!"