I appriciate this Civ. I also made a Frisian civilization quite some time ago. This one looks a bit more proffesinal tough.
There are a few remarks i would like to make. You are using the Dutch name for this people. It doesnt make sence, since the game is English and the Frisan have their own name for themselves(since they have their own language). So i suggest you either use the native name Fryslân or the English:Frisia.
I also cant agree with special unit. Fryslân was at its biggest during the Roman time and during the middle ages, not during the stone age. It would be better to use a swordfighter that replaces the swordman. A unit that is good against the Roman special unit (since the biggest victories were made on the Romans).
Futher more i have a few ideas to suggest. Next to the leader you made now, you could also make King redbad. He is the most famous Frisian king. Another good leader would be Grûtte Pierre (Great Pierre), he is a famous hero, who fought against the oppresion of Holland back in the middle ages.
I didnt install the Civ yet, but i am wondering which cities you used? I am pretty sure you used the Dutch names, but all towns and cities have their own Frisian name. Since there are no real English names for those cities, i would like suggest to use the Frisian native names. I could help you with that, if you want.
Futher more I would like to underline that the Frisian are not a tribe, but a people. The Frisian people are partly ancestors of the English (the Frisian language has quite some similarities with English in pronanucation and words) and Frence. They are now a part of the Dutch kingdom, but in the past they were a independend country that covered a great part of the current Netherlands (Utrecht was an important tradeoutpost)and the German costline untill Denmark.
SORRY FOR BEING SUCH A PAIN IN THE ARS