I picked the knife.
If I put a goldfish or two in my tank I would bet the knife would get both unless the goldy swam straight into the mouth of my endli's.
IME knife but i have only had a tiny birchir so that could change. And their are teo different styles, the knife who goes and gets their food or the birchir who is a more stealthy patient hunter, i like both but have to give the edge to the knife