Yeah, I figured reasonable minds can differ about the division, but I figured it wasn't entirely fruitful to rely on geographical boundaries if it was possible to find a cultural divide (really a combination of cultural and ecological). In reality, the Mediterranean focused on classical antiquity so it should really just be Rome, Greece, Carthage, and Byzantium. But, like I said, I like squares so Spain got sucked in.
Anyway, I just wanted to do something different. I could probably think of other ways to divide it. It depends on what time period you're relying on when stereotyping a region. Certainly, Tunis, Algeria, and Morocco would be with Songhai as a generic North Africa were I not thinking of the classical era (and were it easier to draw squares that included Rome but not Tunis

).