Global Architecture using Sitefinity

What's the best way to handle a large global website?

Our company is divided and managed by geographical region, so we have three different groups (Americas, Europe, and Asia). We are trying to find the best way to structure and architect our Sitefinity solution. At the moment we are going with an all-in-one approach, where all regions are using one database. However, I'm wondering if that is the best way to handle the situation, and maybe there is a better architecture. We are running into some issues with clutter, change management, and autonomy.

Would it be better to have 3 separate databases (one for each region) and then have all three databases installed on each regional server? Then there would need to be some code that switches to the correct server and database based on the visitor's geolocation, language and country code. The code base and solution files would all be the same on each server.

This would just be a way to organize the CMS better. I'm not sure what the best practice would be for this type of scenario. Any help would be appreciated! :)