According to this website the protein and fat in cashews is more or less the same as almonds and walnuts, unless a couple of grams per ounce makes a large difference, which I am assuming it doesn't.
Iron, zinc and copper seem to be significantly more in cashews, 5-10% more in terms of daily requirements.
So many people in alternative health circles believe that we are all largely depleted of micronutrients so perhaps it is these minerals that I need and get from cashews.
I had compared these values before but I thought such small differences should not matter. On second thoughts, perhaps they do.