Yeah… All things considered, I recognize that it’s a bit unrealistic, but dreaming is free XD. If they’re going to add the Nubians, this is the easiest and most logical path in my opinion.
Another thing I’d like to see, after a possible addition of the Nubians (which would require a new architecture to share with the Ethiopians), is the remodeling of the Malian arch set to include more details of Sudano-Sahelian and even Berber architecture (since it’s said that the castle was based on the architecture of the latter). There are, unsurprisingly, many similarities between them.
Some photos to give you an idea of what I mean:
Amridil, Morocco:
Chinguetti, Mauritania:
Bani, Burkina Faso:
Yamma and Agadez, Niger:
Note the relief details of the towers, I would love to see them in the game, at least in the imperial age.
Even in Kanem-Bornu (Chad) you would see some similarities.
Fort Dikwa originally:
In fact, (something separate but related) one of the new features that could be brought into a new Sahelian civ are the fortified cities, sometimes called tatas or saosans, which were widespread in the Sahel from Senegal to Chad:
They could be small, like this one in Atakora, in the present-day country of Benin (not to be confused with the Kingdom of Benin):
Illustration of a possible tata in Paga, northern present-day Ghana (not to be confused with the kingdom of Ghana):
Or real cities, like these in Tiong-i and Sikasso in Mali:
The gates of one in Kyabé and the other in the Mayo-Kébbi region, both in Chad:
And there is much, much more information and images at historum.com, where I found most of them. If anyone is interested, I have the exact links.