Firstly, no one has deprived any faction of creatures. If you don't like the new ones, no one prevents you from using the old ones. And haven't they given something in return instead of magic resistance or ranged attack for creatures? For example, 1.5x damage without a counter or an ability that makes them partially visible/invisible? Invisible creatures are very useful against neutral creatures. And the new dragons will be useful against factions that don't specialize in dark magic or chaos.