It corresponds. Adana is red/yellow and drops red and yellow (or fire and wind) traitstones, and is the ONLY place to get a Red/Yellow Arcane Traitstone. And so on.
And Red/Yellow Arcane Traitstones are only for Red/Yellow troops, such as Moloch. And so on. (Hint - means the mono Arcane Traitstones have limited value!)
Okay, so to be clear, does that apply to the types of Arcane Stones that the legendaries/epics use? I just feel like there are too many possible combinations to clearly determine which Traitstone is for which legendary/epic due to some Traitsones having the same color combinations but different names.
I know Shreggra uses Arcane Lava Traitstones
Shadow Dragon uses Arcane Plains Traistones
Green Slime uses Arcane Swamp Triatstones
The Arcane Skull Traitstone looks purple and yellow to me so I would presume it would be for a purple/yellow card, but what cards is it actually for?
Arcane Skull is Purple/Brown. Plains is Yellow/Purple (which is why it is for Shadow Dragon).
Skull is used for all the Purple/Brown troops of course. So Keeper of Souls, Kerberos, Bone Dragon, Goblin Shaman, etc.
Just want to clarify which Arcane belongs to which Kingdom:
Broken Spire - Shield
Adana - Storm
Karakoth - Death
Zhul’kari - Venom
Whitehelm - Summer
Divinion Fields - Plains
Mist of Scales - Blood
Pan’s Vale - Light
Forest of Thorns - Stealth
Khaziel - Deep
Khetar - Spirit
Zaejin - Forest
Pridelands - Rage
Sword’s Edge - Blade
Ghulvania - Dark
Stormheim - Stoic
Maugrim Woods - Swamp
Grosh-Nak - Lava
Wild Plains - Beast
Darkstone - Skull
Drifting Sands - Mountain
Blighted Lands - Dark
Interesting. So there will be a new kingdom soon. 
Perhaps “ceghhirst” between Kethar and Forest of Thorns
just found the anagram 
Now how did you get that name?
I know someone got an Arcane Swamp Traitstone from Forest of Thorns, which to me would make more sense than Maugrim Woods because the Swamp one is Green/Blue
OK … Forest of Thorns is consistently giving me Water (and Nature). Not sure what the deal is with that.
So I know what that anagrams to…
…but I also know that the next kingdom (and the last colour pair) won’t be that one…
…unless my crystal ball is failing me
I’ve had one arcane and one celestial.
Not sure what I’m gonna do with that celestial yet. Must be something important!
My guess is to unlock the third trait on legendaries?
Third trait of Legendaries needs 2 Celestials. I assume the third trait of Epics needs 1 but I haven’t been able to get any yet. -_-
Can we know the two others traitstones rarity/numbers, plz?
my lucky day. Needed 1 Venom arcane for upgrade… dug out this topic for info where to go, first challenge battle in Zul dropped exactly that.
Then thought it’s such an easy go, the next handful challenges anywhere provided only redundant minor/major stones.
Only problem is that some of the details might be off.
For example, Ultra-Rare’s 3rd Trait actually requires 6 Major, not Runic stones.
But for the most part it’s a good starting point, even liked it myself to easily refer back to. 
Let me see that!..
OK I’m just going to take your word for it, makes more sense anyway. I think I typed that up rather quickly initially.
Nevermind, I found one. We’re both wrong, its 8 Major.