The German word frequency list and word order is only approximate, and you can find the generic reasons for this here. Read on if you want to know the other reasons which are specific to German.
I gave the page the title 'most common useful German words' with the emphasis on on useful, because I ammended the list to such a degree that some of the most frequently occurring words do not in fact occur in the list for reasons that I explain below.
I'm a beginner with German and half way through Assimil German which might explain my thought process, which I'll go through in order.
German has three genders (masculine, feminine and neuter), and each gender has a different definite and indefinite article. It is an inflected language and the articles change dependent on the case required and the function of the article in the sentence.
A list cluttered up with der, die, das, den, dem and so on, isn't very useful.
I removed them from the list which explains why you won't find dem, den and so on (in case you were wondering).
I have done the same with personal pronouns where it seemed sensible.
Learning the most common words is only useful where the words make sense in isolation, and what I've tried (with limited success) to do, is remove the words which don't make much sense on their own.
As German is inflected, words crop up in the list several guises, e.g. mein,meine, meinen 'my' and I have removed all apart from the first instance (and kept the masculine singular).
I have also removed words with multiple meanings such as dafür, dabei and davon. Trying to learn these in isolation isn't helpful. Some words are useful to learn in isolation, others like these are more or less waste of time.
Essentially, as someone learning German, I've tried to make the list more useful and I haven't worried to much about the precise word order. The words in the list are all extremely commonly used in spoken German.
In essence, I've 'excluded a lot of pronouns, possessives and definite and indefinite articles from the word list, but kept some common contractions (where these seemed useful).
As an aside, I've notice some of my other lists, themselves based on the lists from invoke have been copied and used as top one/two/five hundred most frequently used words in French, Polish etc. in various apps and other websites.
But lacking any explanation. Not that it really matters, but I've always wanted to know what I'm learning.
Learning the most common few hundred words is often used to illustrate how to learn a language quickly, the idea being that if you know the most common x words, you can read y percent of the language.
While there is something to be said for this, a modified word list like the one above, is more useful for German than a straight frequency list. There are a high number of German grammatical elements which lack meaning on their own, and knowing them doesn't necessarily help with comprehension. E.g. If you learn den 'the', but don't learn that it is the masculine accusative, and how it fits into a sentence, it won't be of much help with comprehension.
I'm almost certain to change and amend the list over the coming months to improve it and make it more useful for beginners.
I hope to obtain audio when I am satisfied with it.