Are you truly trying to be global, or is your scope actually limited to those countries (fewer than all of them) where your organization markets devices and is subject to the applicable device regulatory system?
In any case, you can usefully divide the world's countries into three groups based on their regulatory system approach:
Tier 1: Countries or regions with comprehensive freestanding regulatory systems, i.e. USA, Canada, EC, Japan, Russia, etc.
Tier 2: Countries with substantial regulatory systems, but which still rely on or make reference to a Tier 1 system or an international harmonization effort which itself is reflective of Tier 1 system approaches.
Tier 3: Countries which have no or only a cursory regulatory system of their own, and substantially rely on or make reference to a Tier 1 system, including accepting approval under such a Tier 1 system as sufficient evidence of local acceptability of the device.
Such an approach to categorization of countries does not actually reduce your work, but it may help to organize and prioritize it. In my experience, large projects such as yours are less overwhelming when an organizational concept is available, allowing you to focus for instance on the Tier 1 countries first since they have the greatest impact on the project outcome.