Donald vs Hillary, Pepsi vs Coke, Whopper vs Big Mac, Separate vs Combined these are life's important questions and the 1st 3 are trick questions because they are all shitty unhealthy choices
There is never going to be consensus on this topic. There just needs to be a final decision on which to go forward with and then actually do so for every system so if it is to be separate then they should all be separate and it it is combined they should all be combined. I personally prefer separate but as long as the situation is taken care of where I can import them separately and get correct regional data then I don't care how it is handled on the DB side