Hiya, I've been trying to expand this article as well it definitely needs information on the HIWI (Russians in German uniform) issue.  Beevor gives good figures on this as well.  I am away for a couple of weeks so I can't check my own copy of Beevor.   If you got chance to check the HIWI numbers when you're checking the casualties it would be very useful.  Also I think maybe there needs to be a section dealing with the civilian experience/casualties, although I should probably float this on the talk page.