I think all articles should be at formers level since people with a deeper knowledge will be using sites, books, etc where that deeper knowledge is assumed. If they aren't already they can get started by reading reading the sources in the article
It is an encyclopedia, not a collection of tutorials. That seems more appropriate for something like wikibooks. Otherwise, every single article would be in inordinately long with a lot of redundancy. I like it better in which pre-requisites are often linked to other pages, so you can brush up on the pre-req's if you don't understand them.
