Honestly I think it is absolutely awesome. Historical Kongo from this period was Christianized, pretty densely populated and strong enough to resist Portuguese for a long time (and win in a few major land battles over them) while sending emissaries to Europe and buildings its religious infrastructure. Furthermore those emissaries were received pretty cordially in Europe.
One thing which fascinates me in eu4 period is how fluent and non-obvious intolerance and tolerance for different cultures was. Vatican received Catholic emissaries from such exotic countries as Kongo and Japan and reportedly received them with great honours. One Japanese samurai traveller went to Europe, his ship crashed and he had to land in France where he became local fame by fascinated people. There were Iroquis emissaries received as a guests on a French court and black skinned merchants, aristocrats and intellectuals in Europe and USA at this time. Hell there was even one very prominent black guy in Russian court. Read that again.
One one hand we had barbarity, cruelty, arrogance and fanaticism and on the other constant crazy intermixing between cultures and politics either being dictated by dogmas or astonishing realpolitik - in eu4 period there was a functioning alliance between Elisabeth's England and Morocco against Spain. England was exporting high tech artillery to Morocco to help them fight against Christians! France has been occasionally allying with and supporting Ottomans as well as standing on the side of Protestants in religious wars despite being zealous Catholic. Armed forces of PLC had very loyal soldiers of Muslim Tatars (they were among the most loyal in the period of Deluge when country was almost annihilated). There were Portuguese soldiers fighting alongside Ethiopians against Adal Sultanate (also black-skinned) supported by Ottoman janissary corps. Dante Alighieri in his greatest work placed Muhammad on the lowest level of hell as Antichrist but in the same time he placed Saladin among the great noble pagan men alongside Socrates, Cicero etc.
The high reputation of Saladin viewed in Europe as great honorable knight never ceases to amaze me. We are talking about Muslim general from the period of bloody muslim-christian wars who dealt devastating defeat to Christians, reconquered Jerusalem and turned its main church into mosque. But he was nice, intelligent and honorable and spared civilians from massacres. It is quite inspiring to find out that at least sometimes quality of a man steppes over prejudices and cultural boundaries.