Exactly,it is the inherited diversity that counts the most,usually found in the larger groups,because the smaller ones are easier to be influenced, manipulated,especially the enclaves.
The autosomal maps that I've posted on this thread clearly show that the biggest Romanian-Vlach populations were Proto-Wallachians,already formed before the Slavs came to the Balkans.
Although the Wallachian genes spike in Kosovo ,like the other Romanian ones,the main differences are that they can also be found in other areas,namely,FYROM and northern Serbia (Novi Sad area).
At least for Novi Sad,it is guaranteed that these are not Albanian or Romanian genes,but Serbianized natives(especially that these genes seem to go westwards, into the Old Serbian territory),the clear difference can be made,since Romanian has Slavic words of Bulgarian type.
In other words, a large population from the Balkans was fragmented by the many barbarian invasions and left its genes into the Albanian,Serb and Proto-Wallachian peoples.
The Romanized part of this population was more successful against the "Albanization", probably because more men have survived the Slavic onslaught,with evidence such as ginere,Latin generis,opposed to North Romanian (Transylvanian and Moldavian)mire,which in Albanian means good.
Which genes are Vlach genes exactly, and how do you know they are?