It is, and I've been mostly using just plain F9 or W9 for those "F9 W9" nations.
Actually, that's a lie. As Mictlan I used Imprisoned F9 D4 B4 Smoking Mirror. Perhaps not the best strategy, but those OzeLOLs, Jaguar Warriors etc etc etc sure tore through stuff, and I even had decent scales from what I remember.
I don't think I've ver used W9/F9, not even in Dom 2 because I'm so leery to take bad scales unless I'm playing AE Ermor.