Quite a good mod, I like your new weapon philosophy.
A couple of suggestions/corrections regarding Kievan Rus.
Let's assume we talk about mid-XI century Rus armies (the thing is that during IX-XII centuries they have changed greatly, transforming from the Northern-style foot armies to typical late-Medieval army with a powerful force of heavy cavalry supported by archers).
1. Troop names.
In Medieval Rus chronicles
archers were called "streltsy" (singular - "strelets").
Now a couple of words about
footmen. "Druzhina" (as you guys call the footman) actually means "an army or a military detachment of the prince". So, "druzhina" is an army, not a guy. The member of druzhina (a warrior) is called "druzhinnik". However, I believe it's not quite correct to call a footman like this, since in XI century druzhina consisted of different kinds of troops (archers, infantry, horsemen). You could call a footman "voy" or "voj" (plural "voi" or "voji", the transliteration into Latin actually depends on the language you are transliterating from). This old-fashioned word actually means "a warrior", so that's a general term, but that's OK for the footman too.
A horseman. Again, "boyar sons" only existed in the head of some crazy developer of the Creative Assembly studio who added this unit in M2TW game. In reality, the druzhina of the prince consisted of the junior druzhina and the senior druzhina. Starting from
mid-XIII century some members of junior druzhina were called "Boyar
children"/"дети боярские" (in plural!). The origin of this name is still debatable, but looks like it was a title (like European "duke", "baron", etc.).
As for XI century, two old Rus names are OK for that troop class. You can call the mounted guy a "griden'" (a full member of the druzhina. Those guys could afford riding cool ponies into the battle) or a "boyarin" (in XI century this word was used to name only the members of the senior druzhina, the best warriors the prince could field).
If you plan to create a military leader for the Rus (capable of blowing a horn

), you could call him a "knyaz" (prince), or a "vojevoda" (erm... voivode, i.e. a general).
2. Weapons.
The super-fast super-long curved Rus blade is not a scimitar but a sabre. In XI century this fast slashing weapon was mostly used by horsemen, while infantry preferred a straight sword or a cheaper axe. Of course, horsemen used straight swords too.
As Trueten has already said, some kite shields (similar to vaegir ones, or the ones Normans currently have) would be nice too, considering those were popular in XI century Rus. The addition of some oval shields would not make this mod worse too

. BTW, I'm wondering why yellow was picked as the color of Rus shields. A lot of chroniclers mention Rus shields painted in
red.
Finally, FYI, some pictures of X-XI century Rus warriors:
http://swordmaster.org/2010/08/18/voiny-kievskoj-rusi-10-11-vek.html
http://www.modelsculpt.org/forum/download/file.php?id=1717&sid=f43f9857dc39150a6e04fbd8c597593a