I dont think warlight uses the brush width values you set on your inkscape file, it just sets it to something like 1.8 (check the wiki, im not sure). If you have a much wider brush it will look as though they are pretty accurate when actually they aren't. If you want to align territory-territory borders well, select the two (or more) territories as a selection (just click one then shift click the other i think), then use the node editor and make sure all the diamonds for the two territories match up. if a border is really detailed and you dont want to draw it twice, you can do some weird path comparision between the two territories (one of which will overalap the accurately drawn one and be really roughly drawn, just so that all the border of the othether territory is covered by that territory). Duplicate the territory with the accurate border (cntrl-D) but DONT MOVE IT! Then while that duplicate is still selected, shift click the territory bordering it, and then go on the 'Path' drop down, then click i think 'difference', it might not be so experiment. To check it has worked, move the well drawn territory aside a bit to check if the accurate border has been copied to the other territory. Move back with undo (cntrl-Z). Hope you find this useful!