It is very hard to locate French sources on Gohrde - almost everything written is based upon mostly German sources. The stength of French forces, you mentiond, is a good example. I have seen up to 9000 stated as being present.
I had more info on the 50e division but it seemed to get lost when I posted. I am particulary interested in a piece of Naps correspondence regarding the division's set up that named officers to be used. Again, I will keep looking.
There was a great interest, in Naps correspondence, regarding the assignment of artillery to the 50e, as well as the other 'new' divisions. The 15.viii.1813 situation has 4 pieces from a foot comp as well as 4 from a horse comp - well, that does get us to eight pieces!
This study has turned out to be quite interesting.