I think it depends on the purpose of the event. If, as I said, it´s a commemorative event, near or on original ground, near or on the anniversary date, then I´m all for limiting impressions to those typical of the actual time and place in history. But your average ¨Civil War weekend¨ or ¨Civil War festival¨ in East Podunk Whereever, is not like that. I think of those events more as ¨tactical demonstrations¨ and it should be OK to have units which never appeared together since there´s nothing historical to recreate in the first place. Like those famous uniform plates in the old Life magazine history. They had no context, but they got a lot of us interested in the Civil War. I´m fine with 79th NY and USCT and Pennsylvania zouaves faced off against Tiger zouaves, Confederate Marines and James River Squadron sailors as long as everybody´s clear that it´s a demonstration of 19th century uniforms and tactics and not a recreatiion of an actual event.