Modder's debate - Moorish Starting position - the most ideal one for modders?

[Hakurei Reimu]

Real-life situation in Muslim Spain and North Africa around 1080:


As you can see, the Almoravids did not even conquer Al-Andalus (Muslim Spain) until 1086. The original Medieval Total War starts around 1087, so it's realistic to make Al-Andalus part of the Moorish starting provinces. But Medieval 2 Total War starts in 1080. Realistically, the Andalusian taifas should be either rebel provinces or a faction on their own.
The Almoravids never ruled over Tunisia or Libya. So Medieval Total War did it wrong.


Meanwhile, in Medieval Total War:

(Almohad starting position, 1087 - btw, Almoravids would be most correct. Also, the Almoravid Caliphate never included Tunisia and Libya. As for Algeria, it was limited to only Western Algeria.)

Medieval Total War, XL Mod

(Almoravid starting position, 1087 - in real life, Western Algeria was part of the Almoravid Caliphate)

Medieval 2 Total War:

(Moorish starting position 1080 - in real life, Southern Iberia did not become part of the Almoravid Caliphate until 1086)

So what is the solution?
Those Southern Iberian cities are rich.
But let's think game-wise.
Rebels don't build or recruit. What could prevent Castile or Portugal from conquering them sooner than the Almoravids?
Nothing. There goes the Reconquista - already ready 300 years before in real life.
There goes also the balance - the Moors limited to Morocco and Algeria only, rather weak. But in real life, Moors were strong.

So.... any way to find the balance between realism and video game balance/playability?
Any way to make find a balanced way, without too much immersion breaking?