Gunter - I came across only one other source regarding your quarry in all my years at the border. It’s… not quite what you’d expect.
To be brief, I was in a Kislevite war-camp when I heard a troop of Tilean pikemen at rest, gathered around their regimental musicians. I know a little Tilean, so I tarried awhile and sought to inquire as to the nature of the lyrics. It transpires to be an obscure folk ballad among their navy, heard on occasion by mercenary companies who travel with them.
I fear this further proves you are right. I fear that slave-raids like that which we witnessed during Tamurkhan’s advance have been going on for decades, but the word is suppressed by the agents of the Everlasting Realm. If the ballad is to be believed… there could be thousands abducted every year.
Listen for a moment lads
And hear me tell my tale
How over the sea from Remas’ shore
I was condemned to sail
The greenskins took me sleeping, sir
And said the dwarf, said he
"For life, Giu Jones, we’re takin yer,
Across the stormy sea
You’ll march yer feet to daemon’s beat
Toward the east you’ll turn
You’ll be drummed to Zharr Naggrund
Or else you’ll surely burn
Or else you’ll surely burn", says he
"And after that, Giu Jones
High up upon the tower’s peak
The crows will pick your bones
There’s no gods for umgi there!
Remember what I say
They’ll flog Verena out of you
And you’ll learn the Great Bull’s way"
The dawi ship upon the sea
Was a fortress of steel and pain
And I’d rather have drowned in misery
Than sail’d to Hashut’s fane
Our smoke blew high upon the sea
'Til a phantom-ship came along
But the dawi on our slaver’s ship
Were a good five hundred strong
They opened fire and somehow boys,
That phantom-ship succumbed
But I’d rather have faced ghost buccaneers
Than gone to Zharr Naggrund
Now it’s day and night and the irons clang
And like poor galley slaves
We toil and toil, and when we die
Must fill dishonored graves
But by and by I’ll break my chains
Well, into the wastes I’ll go
And I’ll join the brave ash-rangers there
Rolf Axenhead and co
And some dark night, when everything
Is quiet in Naggrund town
I’ll shoot those tyrants one and all
I’ll shoot those bastards down
Oh, I’ll give Hashut a fearful shock
When down his priests I’ve gunned
They’ll yet regret they’ve sent Giu Jones
In chains to Zharr Naggrund
Oh, they’ll yet regret they’ve sent Giu Jones
In chains to Zharr Naggrund