didn't they also say they would also harass our territory and take it, and they would fouces most there effort on the strongest faction.
They need to make the nids focus more on the dominant faction or else we might end up with a SM vs CSM all out war with eldar and orks doing a blitzkrieg from time to time....at least that's how faction population seems based on this forum as well as others.
yes nids can take stongholds and if they do there will be some kind of new dungeon (the basement of the stronghold) if you clear this (other factions may go in there too) you get the stronghold back
So the 5th race will be nids? Sorry i'm new here and a bit confused....but never the less I shall purge the foul xenos that taint the land!