nimh, yeah you are mostly right. Supporters of Red Star Belgrade were actually lead by Arkan, notorius war criminal that was later killed in street shooting in Belgrade (mob shooting) and world was shocked by pictures of his "soldiers" kicking body of dead Muslim woman in Bijeljina, Bosnia.
In ex-Yugoslavia there was term "Big Four", refering to soccer teams Red Star and Partizan from Belgrade, Serbia, and Dinamo Zagreb and Hajduk Split from Croatia. All four teams had many supporters and strong hooligan groups, however, Partizan and Hajduk had "just" hooligans, without nationalistic prefix.
Supporters of Dinamo were chanting for HDZ and Tudjman before first elections, but they are best known for their behaviour on friendly game Yugoslavia-Holland before WC90, played in Zagreb. Although Dinamo was excellent this season not a single player was called to national squad so on that game they came in thousands, maybe 10,000 of them and they loudly supported Holland and verbally attacking yugoslavian players. Funny part is that their main symbol were orange jackets and that croatian flags back then were similar to dutch (they cut off the red stars /all yugoslav republics had to have red star on flag) so they looked exactly as dutch flags) and it was actually funny to hear dutch players after the game
"We had no idea that there are so much Dutch tourists in Yugoslavia", "We are happy that our fans turned out in such big number, but we apologize for their whistling to yugoslavian anthem", etc...
As for other yugoslav hooligans, in late 80's it was almost like in South America, all teams had hooligan groups - one of the smallest groups was United Force, supporters of Rad Belgrade - they are serbian skinheds and nazis and they were fighting everyone including other teams from Belgrade (because of their communist names - Red Star and Partizan) and after one game they beat Roma kid (14 years old I think) to death.
In Croatia worst city was Vinkovci. They almost haven't had real supporters group but whoever came to Vinkovci all city was after them. Croats, Serbs, Bosnians, doesn't matter...hooligans, policemen, "average" citizens, everybody was beating supporters of guest team.