I definitely like the idea of bringing weapons more in alignment with the historical period and place.
In university I specialized in early medieval military history (my thesis was on the "supply side" of the Carolingian slave trade, but I mostly was interested in the Eurasian steppe, making Finland somewhat peripheral). Certainly, sword use was no where near as important as historical dramas (and sagas) would have us belief, but held value as status items. That being said, I think swords as long as the bastard swords would not be completely out of place in Finland, but would be incredibly rare and costly (this is a bit late, but interesting:
http://www.medievalists.net/2013/11/grave-of-12th-century-warrior-discovered-in-finland/). The battlesword is probably ridiculous.
Nowadays I look more at early North American history, but the story is always the same everywhere. Spears, spears and more spears. Not only would I like to see more spear types, but I think combat would be improved a lot if spears did things differently.
For example, an Ango ran through a shield should make that shield largely useless, but the ango itself would also be dropped by the user. More variety in javelins as well, from hunting javelins, javelins designed for disarming shields (like the Frankish Angon, which is more in keeping with the traditional ango), longer range javelins meant to unnerve opponents, and short heavy javelins (darts) for bird hunting.
I don't know much about glaives, but generally long, heavy polearms were used in groups and designed to disarm and disrupt the enemy. It could fit, but like I say, I don't know much about it.
A lot of the difficulty is that in this period you had three major physical cultures happening. The coast had a lot of influence from Scandinavian designs and ideas (hence the viking burials and coin hordes), the north tended to avoid fighting if possible and focused on hunting tools, and the interior had a blend of the two. There's a saga where a Viking leader goes into the interior of Finland and is harassed by the locals (using bows primarily) until it got too annoying and left. At the same time there are artifacts from the interior that blend Scandinavian and local designs.I will say "physical" culture though, because there is lots of evidence that Finns joined and possibly led a lot of the Rus activity. So even things that seem too fancy, such as nice swords, crossbows, etc. are still likely to have been present (though rare) in what we call "Driik", "Reemi", etc.
A "weapon" I'd love to see, especially once there are horses, is the lasso. That, and nets, were the common armaments of slave raiders... the Njerps. Something about being run down and lassoed by a Njerp seems horrifying.