@Knez hold on a sec. Look at the headline.
My own maps are based on a thought experiment – what if serbs always saw the drina as a border?
But this has nothing to do with real history which you mentioned by posting a map of 950 saying that bosnia was always under serbian controll – which is clearly wrong as you can see on my map of 845.
Croats and serbs came from north (white croatia/serbia) to the balkans around 630 and serbs lived around sumadija region and later occupied bosnia from weakend croatia around 900.
We participated slavic paganism and south serbs around vardar region got converted first to christianity. Later northern serbia was converted at the same time as croatia got converted. So there is no catholization or orthodoxization of serbs/croats, just the drina as a border between western and eastern influence.