Forwarded this query to Invisible Officer on the Warlord Games forum who I know to be very knowledgeable in this area and his response was:-
"...they are from two Forces. The forage cap guys are Prussian officers with the smaller cap form of 19th century. The others wear Austrian style shakos. May be 1864 war against Denmark. Or more 1890, long enough post 1866 for good relations again."
Hope that helps.