This is my suggestion for a potential new inn unit for Mordor, this is why the post is long.
Again, don't be afraid by non-canon suggestions, I'm just trying to inspire devs.
Unit 1 : Narchost Guardians
Cost : 500
Type : Swordsmen
Lore : "When the Great Plague brought Gondor to its knees in the middle of the Third Age, the keepers of the Black Gate had no choice but to abandon it to Sauron's forces. Yet some of them, clever and strong, bowed before the master of Mordor and kept their previous duties at the price of their freedom, since then tied to the Dark Lord's will by untold spells."
Appearance : Black Numenoreans variation, mid-game infantry wearing Gondorian armors, with dark veins and white eyes, their blood and spirit conquered by Sauron's dark magic.
Lvl 3 : Blood Corruption
Narchost Guardians do knockback damage for a short amount of time. Left click to activate.
Upgrades : Heavy Armor, Forged Blades, Banner Carrier
Unit 2 : Nurn Fishermen
Cost : 300
Type : Pikemen
Lore : "The semi-fertile fields of Nurn served the Dark Lord well during the War of the Ring to feed his endless legions of Orcs and Evil Men. A lot of human tribes living in this region were enslaved to grow crops under the whips of Orc supervisors, but some of them, living on the coast of the Sea of Nurn, willingly joined Sauron's forces to plunder Gondorian settlements."
Appearance : Aztec warriors wielding Inuit harpoons, with precolombian clothes and ornamentation.
Lvl 1 : Porcupine formation
Units form a circle with pikes extended. Batallion cannot move. + 50 % armor.
Lvl 1 : Pillage
Nurn Fishermen steal resources whenever dealing damage to enemy structures. Passive ability.
Upgrades : Forged Blades, Banner Carrier
Unit 3 : Cirith Ungol Trappers
Cost : 400
Type : Archers
Lore : "Built by Gondorians after the War of the Last Alliance, the Tower of Cirith Ungol guarded the second pass granting access to Mordor. After the Great Plague and the fall of Minas Ithil to the Witch-King's hands, the tower was soon invaded by legions of orcs. A lot of them tried for decades to drive out Shelob from the caverns, their hate for spiders only beaten by their unconditional loyalty to the Dark Lord."
Appearance : Morgul Orc Archers, covered in webs and wearing light armors allowing them to spread accross Shelob's lair to hunt down her brood.
Lvl 1 : Poison Arrows
Poison tipped arrows that cause damage over time. Left click icon then left click on target.
Lvl 1 : Experienced Hunters
Cirith Ungol Trappers are immune to poison damage and deal 25 % more damage to spiders. Passive ability.
Lvl 4 : Spider Exterminators
Cirith Ungol Trappers are now immune to knockback. Passive ability.
Upgrades : Fire Arrows, Banner Carrier