Hey now, that's not fair. There's um... and hmm... well never mind
@Bruenor: but what should Arcane do then? I agree that the leaders you mention have an arcane link, but their units shouldn't get 'magic' promotions, so we should fill it in differently then FFH.
Well, yes, a lot of ink has been spilled on the nature of magic in Tolkien which is a very complex topic, often dealing with Roman Catholic beliefs and creation. Clearly there is a complex link between magical power and song, as we see with the first age elves and Bombadil.
A key magic appears to creating items; obviously, we have some powerhouse ones like the Silmarils and the Rings of power. The 'simple' barrow-knives can kill the Witch-King; The Numenorean magic on their walls can hold Minas Tirith and Orthanc under certain conditions. Elrond causes the river to rise at the Fords of Bruinen.
We also have magic that makes new creatures, as Morgoth and even Saruman use to create creatures.
Finally, some basic spells like door locks and openings are used.
Now, getting simpler, if we want to include magic based on FfH, I would probably advocate just 'palace' mana, no mana nodes. We can have a few forms.
Saruman seems to have the equivalent of the domination spell in FfH, it should probably be Saruman specific. I would think the Witch King's 'creations' can be thought of as similar to basic summons like skeletons. We know Sting and Orcrist and swords from Gondolin can behave probably like enchanted blade.
I admit that giving a full range of magic will take a lot of work. However, I envision arcane as of a 'free' trait (like Dextrous) that gives a few spells that aren't overpowering. Magic blade, some damage unead, basic summoning (for summoners, maybe skeletons), the equivalent of create walls, etc. If we do have rituals for powerful magic like ring creation, dragon creation (maybe a tech), we can give these civilizations a discount either for the tech or the ritual.
This topic probably deserves a whole thread.
Best wishes,
Breunor