Well, it is true that the final prize of the HRE mastery is an icon of the famous and much-loved CARLOS V, who in Spain also continues to be remembered by that name, although it is his title at the HRE. It would be hilarious if the Spanish mastery achievement n°14 gave you “Carlos I” icon as a prize, and obviously it’s Carlos V but with another , although they probably give you “Isabel la Católica” or “Felipe II”, or easily all of them.
The detail is that Carlos V himself had blood from almost all the European kingdoms of that time, so he was either spanish and german at the same time. However in military tactics, depending on the situation, he took advantage of the armies of the Kingdom of Castile and Aragon or from the Holy Roman Empire. For his invasion of the Vatican for example, he used a massive army of tens of thousands of Landsknechts, but for other invasions he used the famous Spanish Tercios.
It is true that if the history of the reconquest of Spain is marked in his campaign, there is much to talk about and not only about his battles against Muslims, but events such as the invasion of Constantinople in the 4th crusade for the Crown of Aragon; or the occupation of the Kingdom of Sicily, or the conflicts with France and England. It could also cover the period of “El cantar del Mío Cid” at the beginning, in the middle the Battle of Las Navas de Tolosa, and end with the Conquest of Granada.
Of course, the civ “Al Andaluz” could be considered as a campaign Civ, or also include the “Sultanate of Morocco” as a new official civ, which both at that time became 2 very different kingdoms. I actually made some concepts of both civs, but haven’t revealed them yet, mainly because I like to be very detailed with my models, and I’m still working on a new one, but sometimes I get lost, because recent post make me want to modify my concept of Incas and Aztecs, and I think I have finished the Inca, but the Aztec still needs 1 or 2 tweaks.
In theory, Al Andaluz would have as Landmarks many palaces and structures of the famous Alhambra in Granada, a “Network of Castles” Bonus similar to the English Bonus, and as unique units: the chained Royal Guard of Granada and the Genitour.
The Morocco civ. would have a system of dynasties similar to the Chinese, going through the Almoravid, Almohad, Merinies, and Saadi. To go through each dynasty you have to build 2 landmarks. They have many unique buildings, including a fortified granary and fortified mosque, and 4 unique units for their 4 dynasties.