I've been looking at your post trying to think how I can answer it concisely. The details of that conflict were so intricate that I don't want to go on and on. While I'm certainly no historian, I've done considerable study on the subject during my academic career and lived in the Balkans. "Once Brothers," largely due to the inconceivable structure of giving an open and uncontested mic to Vlade Divac, views like a piece of Serbian propaganda....
...I just deleted a whole bunch because it really is a rabbit hole. But giving an open and uncontested microphone to a nationalist about his feelings over the balkan conflict, and about a former friendship that disintegrated due to his own behaviors, was shockingly poor documentary design. The fact that everyone who knew Drazen was well aware that his best friend was Stojko Vrankovic (also an NBA player), and that Stojko was for some reason not the logical counterbalance for Vlade, is really bizarre.