Consider grouping similar countries. If the target country's language is the same, put them in one campaign. That way, it will be easier for you to manage them and make adjustments.
Things get a bit more complex for iOS. Due to new limitations in the SKAdNetwork framework around removing country information, advertisers must limit their combinations of live campaigns and creative packs to 50 per app. This will help you obtain more accurate SKAdNetwork reporting by supporting the correct association of installs to campaigns and creative packs.
This change increases the need to group countries within campaigns. However, consider targeting your most important countries and regions in their campaigns for better performance and reporting accuracy.
For many advertisers, the US is a significant market. If the US is grouped with other countries and a campaign daily cap is in place, please pay close attention to the daily cap distribution. This will help you ensure that not only one geo consumes most of the daily cap and leaves the other geos unexplored during the day.