I prefer to hire someone with experience vs. text book training only.
But it's a f'd up question to begin with anyway.
You need the "textbook" explanations to understand the process, and you need to manually do the process/technique several times yourself to fully master the technique/process.
You need both.
Now take for instance, oh..say chocolate tempering. I get culinary students in from time to time for 2 week stages. I'll show them how to temper and explain the basics, then grab a book of the shelf, stuff it in their hands and ask them to read up on the subject more in detail on their own time. Every book I own and lend out to students has isbn #'s, "suggested reading/related topics", and more than one jump-off point to gain broader book knowledge on various subjects and techniques.
How resourcefull, and how hungry they are to learn more is entirely dependant of the person....