My assumption was based on having to reskin most of the factions and the coding and scripting will have to be re-worked. I wasnt trying to say it was impossible nor was i being literal about it. I think i just meant that it wouldnt be as easy as say "War of the Usurper". Sorry Im still new to modding.
However this Idea I think is Awesome. I love any case where you can rewrite history in your own fashion. Especially one so fun and rich as Westeros.