The Drath recruitable unit for Kingdom faction costs way too much time to train.
The problem lies in a faulty equipment design for the unit.
For comparison, here are the training times for all recruitable units.
Ogre 3
Drota 5
Darkling 5
Umberdroth 3
Demon 3
Shrill 3
Spider 3
Dragon 3
Drath 15
The problem lies in the fact that a Drath unit, by design, wears a GreatScimitar. However, in the weapon balance pass in 1.08, the training time required to train a unit with a GreatScimitar was increased from 4 to 12, bringing the training time for a drath unit from 7 to 15.