OK, so assuming there isn't much in terms of changes, mechanics-wise:
Nords absolutely rock in terms of ranged units. In the previous versions, the Nord Snipers could and would beat armies three times their size if you used them cleverly. On the other hand, an all-Sniper army has NO means of fighting melee, making them a joke in terms of close combat. Teal Deer, don't let the enemies get close or you are thoroughly ****ed.
On the complete flipside, Khergits and, apparently, Sarranids, wear melee weapons to a man, with the former being more horse-heavy and the latter infantry, from my experiences in this version.
Swadia is well-rounded, with pretty much all types of troops receiving equal attention, but none excelling.
Rhodoks I don't know much about, they seem to have decent sharpshooters too.
Vaegirs are also quite balanced, but lean more heavily towards close combat ranges with the lack of DOOMSNIPERS and SMGs and ARs wielded by some troops. Top-tier are stormtroopers, but I didn't get to them yet.
Helvetia has a really short troop tree (Recruit->Soldier->Lieutenant -> Either Black Coat or Spec Ops) and troops wield sabres, so they can hold their own in close ranges. Don't know much more.
Balion seems to have snipers of their own, although less powerful and accurate rifles for them (might be faster though), and I think some machineguns, but I haven't really delved much into them.