There are people who are really into this stuff, much interested in even minutiae details of OOBs. To me, it's just a nice source for a quick overview. Some readers may be interested in this little gem, though:
update: newer version link
The Bundeswehr had 36 active and 12 territorial army ground combat brigades when there was still a real national and collective security challenge (the U.S. had then only 16 in Europe including the ACRs).
Times have changed - today we can make do with a fraction of it and still no red, yellow or pink horde invades us or an ally. You probably wouldn't guess that the national and collective security situation is so utterly relaxed if you read only anglophone sources on defence, though. There's a lot of hysteria in comparison to 'continental' ones.