Let me share my thoughts about Córdoba:
Since the actual Caliphate of Córdoba lasted from 756 to 1031 and was the golden age of Muslim presence in Europe (later desintegrating into taifas and becoming part of other empires), I think Córdoba qualifies as one of those civs that should concentrate on winning quickly rather than trying to build a long lasting empire. As such, I would like to see the last UHV, Control 4 cities in Iberia and 4 cities in NW Africa in 1490, changed, especially since it is so easy.
I suggest: Control Iberia and Southern France in 900. This means that the player will have to take military action quickly to conquer independant Pamplona, Barcelona, Toulouse, Burdigala and Marseille. 900 is right before Spain's spawn, therefore there is no need for a conflict with them (there will inevitably be war after anyway). This is historical, as the Muslims quickly took hold of the Iberian Peninsula (except the NW, but there aren't any independants there anyway) and parts of France, although the UHV would require to win battles that were lost by the actual Andalusians (Charles Martel...).
I tried to achieve this and I am positive it is quite possible. It requires early military focus and the hiring of mercenaries, but at the same time making sure the capital grows to be the largest city. Although by lack of ambition I stopped at Toulouse, I was still far from 900 and could probably have taken Burdigala and Marseille had I wanted to. However, my economy was in ruins and I needed to prepare for the arrival of León (and did not want to risk a war with the Franks or the Burgundians). I believe it would be a great challenge, far greater than just sitting there with no real goal except growing a city.
The other 2 UHV are okay, although building the wonders is perhaps too easy.