As an Argentinian I can tell you the most realistic tango style I heard is in the Korg Pa series called Argentina Tango. The rest of tango styles in the Yamaha arrangers are very european. You should know there are many forms of tango, the classic, the Piazzola and others. Check the videos in this web site I found to see how tango evolved through the years:
http://miescueladetango.blogspot.com/2009/03/existen-estilos-de-tango.html I'd like to make it clear that I don't know much about Tango. I don't play those styles. I only like the Piazzola tango which is very orchestral (no singers there).
Victor