Hmm, I see. I was just thinking sense some romano factions are half roman half barbarian, maybe we can see that concept in the units as well. As for a unit model that uses it...the best one that I know of that actually describes the type of unit that I was referring to is the Bucellari Guard Axeman from the Last Roman Expedition DLC for Attila Total War lol. Although that unit probably never really even existed in actual history, it does add a nice to a Romanized Barbarian Army in my book.
Here's a picture...I hope its viewable...