No you’re panicking and reaching my dude. Serbs in Croatia can point to the exact migration patterns their ancestor undertook to the Krajina frontier primarily from Serbia and Montenegro. Many were invited to help populate the military frontier.

And those same Serbs are called as Orthodox Vlachs in Bosnia and Croatia by nationalist Bosniaks and Croats, they negate their identity because they did not have a defined Serbian national identity until the 19th century. Obviously, they are Serbs today, but identities in the Balkans before the 19th century were not fixed and were not even particularly important. There are even medieval Serb documents that distinguish Serbs and Vlachs, look it up.

I’m just simply asking, out of curiosity, what were the mass migration patterns that Croatians from Croatia undertook the settlers the lands of BiH?

What kind of logic is that? Migrations? So according to your logic, someone from the Dalmatian hinterland is a Croat, but someone just across the border in Herzegovina is not, even though they are literally the same. When did Serbs supposedly migrate from Serbia to Montenegro? Why are there Serbs there if the country is called Montenegro and Montenegrins live there as far as i know? Also, look up early medieval Croatia, its first županije reached up to Vrbas and the Neretva. But this should not even matter. Look up Turkish Croatia and Turkish Dalmatia during ottoman times.

As far as I am aware, Croatians in Croatia proper, consider you people as “Bosanci”.

As far as i am aware, Serbs from actual Serbia call Serbs from Bosnia as Bosanci, those from Herzegovina as Hercegovci, those from Montenegro as Crnogorci, those from Croatia as Dalmatinci, Slavonci, or Krajišnici, and those from Kosovo as Kosovari. Why do they still call themselves Serbs by your logic, and why do they often act like they are "bigger Serbs" than people from Serbia itself? Is that the logic you are looking for?