Right, obviously Amazon total war was put on RTW because thematically, notwithstanding being mythical tales, they're associated with the classical era. I suppose you could put classical Amazons into the medieval period and just say they survived into that period but its a bit jarring.
Since I just watched Thor the movie, I thought it might be good if you used the Valkyrie from Nordic myth as both a reason to include them, and for a plausable faction. Granted, they're a prechristian myth but they're still close enough that they wouldn't look out of place alongside medieval units. Plus anyone who's played Skyrim knows that its fairly easy to amalgamate norse and medieval ascetics. There was a similar idea on Four Seasons with a quasi-Amazon faction called Valkyrie but the ascetic wasn't remotely nordic; more like high fantasy dragon plate in yellow, red n blue. Really it should be smooth plates with norse runes etched to it on top of furs. Again, Skyrim is a great example of this.
(to Parthian Shot personally: I know you're okay with it. But norse=cold and I don't think the poor lasses would be wandering the snowfield n forests naked. Thats just needlessly cruel.)
Since Norway n Sweeden are rebels it'd be a pretty convenient place to slot them in.
Also does anyone know of any Arabic or Muslim tales of communities of warrior women? Anything in Sinbad? Just rolling with norse warrior women would be a little stale.