I was thinking for the rangers maybe some sort of like powerful captain, for near harad the oliphaunts, and for the blue mountains just something like maybe a powerful war hammer unit.

For a Faction that should get a general upgrade, I'd say the Morwaith or maybe Dunland. Both Factions are quite simple in comparison to the others and are kind of boring...

As for which Faction needs a special unit... all of them? Only a handful of the current Factions have a special unit currently, and this should (and probably will) be extended to the others.

For me, maybe Dunedain...

I think Bree is the best choice to an upgrade. It's quite empty of interest, actually. Besides the touristic opportunities with Bree ant other towns as fixed structures, it doesn't propose anything.

For the person asking about Morwaith, I found reference to morwaith mercenaries who slew Gondor leaders, they were sort of like assassins. They could possibly be a unit similar to rangers in that they can hide from enemies. Additionally, Dunland could definitely use some buffs, maybe if you have enough negative alignment with rohan the price for units lowers to be cheaper than any other factions.

Lol, the Rangers need a nerf, not a buff. Not a single unit in middle Earth can see them when they turn invisible, and they're not even a special unit. They have the same health as the Uruk-hai, can turn invisible, and are both archers and melee fighters. What else do you need? a dwarven quality armor? Why bother playing Gondor or Rohan at that point? Rangers dominate the map on the official server. What we need is to make the invisible rangers a special unit that costs more silver coins while also adding a melee ranger with long sword and without a bow and invisibility that costs less to hire. that would make the faction more balanced and add more variety to the boring faction.

As for for the other two, non of them can have a buff without a nerf.

Well, he told about an upgrade, not a buff necessarily.

Morwaith mercenary exist

Just not invisible

I think both Rangers and Blue Mountains need new flavor. The only structures Rangers have are camps, watchtowers, and villages (ruined arnor towers if you count them) while BM have only houses, mines, smithies and strongholds. Near Harad has plenty in comparison, they have 3 crafting tables, 7 armor/weapon sets, 5 subfactions, and 20 structures. I voted dunedain because I am more used to how empty the ranger faction feels. But now I've realized that the Rangers feel more empty than the Blue Dwarves because I spend almost zero time in the blue mountains, because it is so boring. Blue dwarves (just all dwarves) are the ones most in need of an expansion. Even though Morwaith have less than the dwarves, the dwarves have official lore and are in the middle of Sauron vs. Free Peoples.