Why would they have to co-exist? If the Chantry is right, Cory is the reason that the Golden City is the Black City. That was only a thousand or so years before Origins. The Veil already existed then, since Cory and his cohorts had to go through the Veil to physically enter the Fade. Their stated goal was to enter the Golden City, because that was the supposed seat of the Maker. So it wasn't Black then, or they'd have had a different goal.
Do you know we use to thing the sun revolved around the earth. Lack of knowledge and perspective effect who people see the world around them. Just because it's called the golden city does not mean they actually saw a golden city in the fade.
This is not the first time the golden city was spoken of. It's taked about in the saga of Tyrdda Bright-Axe.
http://dragonage.wik...e,_Avvar-Mother
Second stanza:
Thelm Gold-Handed, fingers greasy, jeweled rings
with glitter shone,
Took in tribes in times of trouble, fed them fat to
weaken bone.
Warriors great and great in number, sun-kissed
swords to fight his wars,
Drake-scaled shirts their bodies covered, heart-wine
stained the salty shores.
Told his tribes a tale of treasure, over sea to north
it gleamed,
Whispered words to drive the droves to golden city
where he dreamed.
Counseled quick in dreams alone,
Voices wiser man ignores,
Pushed the tribes until they screamed,
Heed the dreams and cross the Waking.
Fourth stanza:
Tyrdda Bright-Axe, Thelm Gold-Handed, battle
brought with blade and ax,
Thelm in mail and shields of silver, shining sheen to
turn attacks.
Blade of dragonbone, now blooded, warrior throats
wrung raw with cheers,
Tyrdda stands, her bright ax blazing, leg still
weeping battle-tears.
Bright the ax of leaf-eared lover, laughing lady of
the skies,
Fire flares as Thelm Gold-Handed, honey-tongued,
repeats his lies.
"North to warmth, and golden cities,
Whispers speak in Dreamers' ears!"
Silver scorched, the liar flies
On raven's beaks, to dream unwaking.
But it states the guy, Thelm, was only told about it by spirits in his dreams.