Small Scale Military Headquarters

I was at a WW2 reenactment this past weekend and there were some horse drawn wagons, including an ambulance. Where they used on the western front or mainly against the Russians.
And is there a site that might have pictures of them.

They were used on both fronts. In fact, a significant portion of the German army relied on horsedrawn wagons throughout the war. They simply did not have the industrial capacity to produce massive numbers of transport trucks and utility vehicles like the US did. Then there was the problem of inadequate oil (and hence gasoline) supplies once the US was able to bomb the Polesti oil fields in Romania.