Originally Posted by
uanime5
The vlastela is incorrect, it should be Khmer Heavy Swordsmen.
The Ghulam Dynasty of Delhi is called this because it was ruled by the Ghulams (slaves) of Muhammad of Ghor after his death.
Many of the special units are not available until 1400 or 1500, such as Gothic Knights, because the technology needed for them doesn't exist.
Some units don't have any armour upgrades because the faction only used light units (especially in hot climates). Other units cannot be upgraded until a certain time period, for example Plated Knights cannot get Full Plate armour until 1400.