@Knez Knez to Knez  ;) I`m not biased. You have a lot of Croat mentionig and historical sources for BiH. Espec for those ones in Western BiH and Herzegovina, and those one in Posavina. Central BiH Croats have mixed heritage. Due to Catholic Church most of the Catholics from that area embraced Croatdom. It is simmilar for Orthodox Vlach all around BiH. After some time they embraced Serbdom. Just check Dušanov zakonik. He clearly differ Serbs from Vlachs. Check the serbian sources about army ethnic background in Serbia from 18. and 19. century. There are a lot of sources, just need to check. I`m here for any other propper argumental conversation. Good work Knez  ;)
PS You can hardly found Vlachs in costal area of Croatia. 
For Turks that term was used for anybody who works with cattle and pay tax called filurija. Turkish term Vlach and Vlach as ethnic charateristic are two different things