I personally dislike the Expell The Jews! or Invite the Jews! Option in MTW II Total War. However, I think that countries that have a more moderate view on religion, especially with an emphasis on banks or merchants should have a higher chance of attracting a Jewish Population. Once a certain percentage of Jews live in a province, lets say 5% You would unlock an option to build a synagogue, which would in fact attract more Jewish Immigrants to your country, and perhaps lower Jewish Populations in other areas without a synagogue. Of course this is all relative, because not all Jews were great bankers and merchants, just like not all Muslims are zealots. However, the option of being more religiously moderate would have some advantages and some drawbacks, the advantages being that in such a society people were freer, socially and politically, and people had a better chance of having an education, thus VIPs from sed region would be more likely to have increased Acumen and Diplomacy. On the other hand, a conquering faction that was too moderate would face difficulties, such as a Catholic Faction would have a lower relationship with the pope, and more likely candidate for excommunication, Once a region is conquered, it's subjects will be free to practice their own religion, have a MUCH reduced conversion rate to your state religion, and a higher dissent rate, which would result in a lowered income from taxes from the region, as Fanatics are much less likely to deal with those peace loving Christians, than to just smuggle their goods, and keep whatever they make to themselves. Also, if a region has a high percentage of muslims and Christians, the likely hood of the two peoples merging into fighting regiments together would be highly unlikely, so if a region were to be split equally between Christian and Muslim, some regiments would be made up of entirely Christian Men, and other regiments made up completely of muslims. And if the muslim population doesn't respect your rulership, and your a christian king, chances are they won't take up your call to arms.