Heh, I don't really know what they were thinking with Helheim at a glance. Give everyone glamour and make them cheap and good? I mean, they've got some oddball path combos on some of the mages, but they're hardly useless with access to both death (good enough to forge boosters too) and blood (Storm Demons, Devils, and Demon Knights are realistic and empowering them to do that isn't a big deal as they won't die of old age). I guess I'm not seeing what their downside is for having such strong national troops. Definately one of the stronger nations.
I think the Vanheim set always had really strong national units. It's just that in Dom2 supercombatants and mage armies were so dominant it didn't much matter. Now that magic's been seriously toned down 20 defense units which usually ignore the first hit or two due to glamour are just killer.