I cannot separate pages dedicated to different regions/languages between AWS buckets in different locations (pages are NOT on separate sub-domains, e.g. en.example.com and de.example.com, instead, pages are structured as example.com/en and example.com/de)
So, is it worth placing German sub-pages in a different bucket in Frankfurt AWS region and redirect all requests to example.com/de (that is placed under main London region for example.com domain) to the separate bucket? Will location-related ping decrease overweight ping increase caused by redirect call?
Similar question applies to Tokyo, Ireland and Paris regions comparing to the main London one.
If you're hosting out of S3, then I presume all of your content is static.
I would start with using Cloudfront, and if you really wanted to you could have separate languages mapped to separate buckets in different locations - i.e. /de/ could map to a bucket in eu-central-1, /en/ could map to eu-west-2, etc.
However this should have little impact on the performance your end users see, since they should be retrieving content from the nearest edge location.