Sure it wasnt biblical but it wasnt minor either,im of course refering to the so called great serbian migration in the 17th-18th century
All the sources i managed to dig up(mostly wikipedia) mention either some patriarch leading 60k people into hungary,another serbian source says 60k families.
In either case its a lot of people.
Also i was only trying to think of a plausible way to get what the author of the thread requested,nautral migration during the original serb migration a millenia ago isnt going to work since they werent a maritime people to begin with.
The only option is for the habsburgs to subcome to their catholicism,all it would take is their king being a bit more zealous fearing for his immortal soul which wasnt that uncommon back then,then the serbs have no choice but to either make a stand against the turks and get killed off or flee to wherever they can
Also i still fail to see what venice is going to do with them,its between 60,000 and 180,000(if every family has 3 people) people they would need to settle in dalmatia or risk them simply taking it over from them,ragusa is in even worse shape because they could realistically siege the city itself with little chance of relief.
I also dont think the transportation is that impossible of an issue,venice had very large amounts of ships and if they work together with the ragusans they could probably get rid of them in a matter of months.
As for venice not wanting to piss of naples,in all honestly naples is irrelevant to the venetians,their heartland is in the northern adriatic and most of their trade flowed from the east,weather naples likes them or not is compleatly irelevant to them,not like their relations with most of the italian nations were that shiny to begin with.
If anyone has a better idea to make this work im all ears.