I'm not contributing to Wikipedia, I'm just an user, so I cannot judge their deletion policies.
Though, I would like to criticize the statement
"Quality though, is often considered to be higher on the German Wikipedia."
Quality is not measurable directly. It's just a subjective thing. If you find quickly the right information for you - the quality is good. If you don't find it - you try somewhere else. In this case, your personal quality standards haven't been satisfied.
This is where the deletion policies come into. Now if they tell "We take quality over quantity" - it's OK. But this isn't the case. Most articles are poorly translated from english to german; if you browse for some biographies (let's say Jimmy Page for example), there isn't even a terminology (missing the eye-catching information).
Or even browsing the periodical table of the chemical elements - you get some information, but it isn't presented well. I'd rather like 750k high-quality written articles than >2M poor transcriptions from en.wikipedia.org or somewhere else from the www. That's where de.wikipedia.org is right now. They cannot meet they own quality standards, whatever that means. One day, they will understand...
Even if they don't have that much contributors like en.wikipedia.org - they are doing a good job (ok, at least they are trying).
As a student of physics, I prefer a thing called "book" or "paper" to be my primary source of solid knowledge (OK, not always but mostly). Considering Wikipedia in a scientific work, it is just fine if you need "quick and unimportant" information to verify something, because you cannot always attach validity to such a dynamic source.