For some reason, I can't build all the units that should become available after constructing the necessary buildings. I am playing as a dwarf warlord, and after constructing the required buildings (e.g. Great Beast Lair), the unit production just doesn't show the higher tiered units (e.g. manticore). Same across all my cities. and also for other conquered races (no T4 units). I'm getting very frustrated, I can't figure out what I should be doing. Can you please help me?