[PDF]

IMHO it's just N9 that matters for Niefels, you can rather easily gives the Jarls reinvigoration and quickness through items (making Jarls thugs/SC is THE way to go with Niefelheim).
Also Son of Niefel is also better than GM (who usually kills herself by trample fatigue).
Lastly I don't think Niefelheim is easy to play effectively in MP : super expensive troops, uber-crappy research until you get Sages...