Legitimacy of pre-approval tools for a beginner?

I'm looking to open my first credit card- recently graduated, just started full time job with pretty decent salary + living at home. As everyone recommends, I was looking at discover vs capital one quicksilver/savor. However when using the pre approval tools, I was only approved for a secured card from discover whereas capital one approved me for the unsecured savor and quicksilver (with $39 AF).

Now I'm questioning the legitimacy of capital one's pre approval tool, and don't want to be denied. Should I apply or play it safe and go the discover route? Wasn't really planning to put down a security deposit but can if need be. Are pre-approval tools generally accurate?