To say that most Greman reports has been complete lost is WRONG in my meaning. A lot of these are still locked down in German archives... :'(
The German Army and many Army Corps reports were already micro filmed by the American for over 80 years ago..
The problem is that NO ONE have read them, perhaps the Americans cant handle the language or they are afraid of the result of these reports..??
The Army reports contain very vital information(I have read some of them) like for a example, a certain day in October 1918 one of our Fighters was shot down in No Mans land and the pilot got safely back. However these reports seldom contains actual names...
Another example could be that four of our balloons within a certain area were attacked and one was damaged..etc..etc
The Army Corps reports are even more detailed...
The German statistic of losses are also nearly 100 % correct, the problem is to break it down to day by day basis. The book CGAS has started this project in a public way. But I am convinced that some German historians could add a lot of material regarding this.
I would say that the most difficult period to clear up is the early period 1914 until mid 1915...
The sad thing is that either NO ONE seems to have read the allied equivalent....I would thought it would easier for example to read English texts..