No worries, I didn’t mean to suggest you’re asking too much questions here! ;) You are absolutely right that these automatic identification services aren’t perfect. WhatTheFont only recognizes those fonts that are available from MyFonts (which are many, but far from all). As such, it can’t find Pícara. What Font Is – as a service not tied to a single distributor – finds fonts from many sources, including free and open-source ones, for better or worse. It has its flaws, too.
When I saw Linotype Bodoni (a classic), I thought “hey, Fiz could have found that one via these services much quicker!” … but now I realize my bias: I could only think that because I had already recognized the font. When you don’t know the font, you obviously don’t know whether it’s a classic, or whether it’s part of the MyFonts catalog.