ahte
Chieftain
What I actually see in this picture is a lot of "ninetys/fortyfives" in the upper background ( the middle part is actually looking like a checkerboard pattern ) which lends to the conclusion that it is some artificial ( not natural ) structure in the background.
You mean like, perhaps, windows?
Spoiler :
I personally still think this statue of Osman I is the real-life picture that is the closest match to C5, just from a slightly different PoV:
Spoiler :
(Depending on how I look at C5, I can either see a man in a turban looking right, or a man on a horse looking left)
And maybe I'm trying too hard here, but in this pic you can see that around the statue are apartment windows:
Spoiler :
If we imagine moving the camera to get the angle that matches C5, those windows could end up behind the statue - could that be the cause of the dark blobs you can see in the background of C5? (esp. top right corner)
Also, of course, the Ottomans fit the alphabet pattern, and BEST PROOF YET the Ottomans have featured in Ed Beach's board games so he's clearly a massive fan!
I'll shut up about this theory after this, but I will be back to say I told you so when we see the original picture!