So according to your point, Turks were right to slaughter armenians in the name of tribalism and the good part of history in the Balkans were the time were everyone killed those of different ethnicity?
I don't think that tribalism saved armenians (eventho they were practising it too) neither did it prevent people from being killed in the balkans.
You are right only on one point:
You may eventually learn that casting off your ethnic, cultural, tribal identity doesn't really mean much if the people you are doing it for don't also do the same. In fact they are encouraged to do the exact opposite.
It is indeed pointless to destroy tribalism in Europe if we import it from other countries, reason why immigration should be regulated and the immigrants should learn to respect other beliefs and traditions.
Destroying tribalism is not followed by a vacuum, it is followed by the understanding that your neighbour doesn't need to do exactly what you do so you can leave in peace. If you don't mind what your neighbour do in his private life and he is not minding what you do in yours either as long as it doesn't bother the other, then you'll be able to live in peace. Otherwise you will always find a new neighbour who does something different, and there will be no peace until everyone on earth has the one same culture.
Plus this "vaccum" seems quite powerfull to me as second generation immigrants from the Balkan are giving up their tribalism and mix with each other very well here, many of my friends from Kosovo descant have serbian friends and vice-versa.
I am not saying french, german or european culture is non-existant. I am just stating that having different culture is no reason to reject or kill each other and that is the motto that made Europe peaceful and stable.