Ghost Bear said:
I was surprised to read that, to be honest. I always assumed that the Brotherhood was a Sommlending institution.
I always assumed that as well - basically, the city of Toran is divided into any number of guilds, and the Brotherhood of the Crystal Star is the Magician's Guild of Toran (stated a number of times).
While guilds show up in a number of other places, we never really see a magician's guild anywhere else (unless you count the Sages of Varetta... but they're certainly not part of the Brotherhood).
Personally, I tend to see the Brotherhood as being a Sommerlund-exclusive group (like the Kai), and that the RPG simply made the multi-ethnic reference as a means of making them more playable.
But I also feel that it's not impossible for other nations to have similar methods of magic (in much the same way that the RPG links the Magicians of Dessi with the magic from Grey Star, which never really made much sense to me), so a Gamemaster could easily either assume the Brotherhood is all over Magnamund (the easy way), or could develop a slightly different version of the Brotherhood somewhere else (with a different name, different ranks and hierarchy, etc).
As for Helghasts being the more powerful military force, I always got the impression that it was impossible to "mass-produce" them, as it were, so at any given time, you'd be hard-pressed to get more than a couple of them together in any one place (because, in order to concentrate them in one place, they must neglect another).
In other words, Helghasts wouldn't HAVE a military rating, as it were, but their presence could either bolster the effect of the army they support, or hinder the effect of the army they oppose. So, if you're ranking different militaries by number, I'd say use the Helghasts as a modifier to that number (say, boost by one for every Helghast present?).