In most games I play, northern Empire performs much better than Sturgia. In that one I played today, I joined Sturgia as Merc when they were at war with Northern Empire. NE had some more enemies, but survived long enough. then they made peace... and instantly Battania, Vlandria and Khuzait declared war on poor Sturgia. Within a year, Sturgia had lost 3 castles and 2 towns, and numerous battles. And with the special design of the map, you can't build up a reasonable force of Sturgan troops once the enemies took Ov castle and Varcheg, and use those as bases for roaming troops. You can't evade those f.... enemies while collecting troops because of the silly map design... I had to cancel my merc contract to avoid getting broke.
And I still think the lowtier Sturgian troops are too weak, specially the "ranged". The Woodsmen are no match for imperial archers or Vlandryan levy x-bowmen, not to mention Khuzaits.