Armour abilities - a balancing act?

[Andor]

One of the themantically interesting things in 4e is that some armour and weapon enchantments are limited by type.

Is this just a flavor thing, or is that part of the balance between armour types and class armour allotment?

To sum up:

Cloth
Bloodthread
Darkleaf
Delver
Fireburst
Ghostphase
Magic
Mantle of the Seventh Wind
Shadowflow
Sunleaf
Sylvan

Leather
Bloodcut
Darkleaf
Deathcut
Delver
Elven Battle
Magic
Shadowflow
Sunleaf
Sylvan

Hide
Barkskin
Bloodcut
Darkleaf
Deathcut
Delver
Elven Battle
Magic
Sunleaf
Sylvan

Chain
Angelsteel
Barkskin
Curse Forged
Delver
Dwarven
Eladrin
Exalted
Magic
Tombforged
Troll Skin

Scale
Black Iron
Curse Forged
Delver
Dwarven
Hydra
Magic
Razor
Troll Skin

Plate
Battleforged
Black Iron
Delver
Dwarven
Flamedrinker
Magic
Mountain
Soulforged

Huh... Interesting list. Some look like flavor to me, like Eladrin Chain. Others are simply nods to what classes will use them like the Shadowflow armours. What about the rest? Flavor or balance, and why?

Edit: I notice that all the armour types save Leather and Hide have enchantments unique to themselves. Why not those two? Too similar?

 

[Andor]

Not one conjecture?