Why do the Byzantines get all the historically inaccurate fun?
Why isn't there a gigantic amount of potential gameplay about the Muslims reconquering these areas? Seems unfair, s'all I'm saying.
I fully agree with you in spirit, and frankly it is unfair - but the way the game works, unfortunately, it's actually far harder to survive as Granada than as Byzantium (despite historically Granada being far, far more powerful and resilient than Byzantium at this point), which coupled with the generally Christian-centric focus of the game means that Byzantium gets as many unique missions and decisions as the most major countries in the game and Granada just gets the complete weirdness of missions intended for Catholic Spain if any skilled/lucky human player deconquistas the peninsula.
Still, if anything was to be fixed by the devs, the terrible situation where Castille by itself can overrun Granada and North Africa in 10 years would have to be the first priority.
That being said, a mod which aimed to give every country tag the same level of flavour and unique missions/decisions as Byzantium has would pretty much be the best thing ever, IMO.