How much impact does population and attraction have on youth intake?

Firstly, do either of them have any impact? Wouldn't make much sense to me if they didn't.

Secondly, for example, if I am to start with Hoffenheim in Germany, their 'city' is set as Hoffenheim which has a tiny population of 2,501-5000 in the database and a classy attraction of one.

Does this mean without a very, very good youth recruitment I'm going to be taking absaloute crap players in each year without a huge piece of luck? Or will I generally be taking players from the local region anyway which has a population of 10.7 million, therefore meaning the tiny population of my city etc isn't massively relevant.

Cheers.