There is a multilanguage site which has several payment and shipment methods. It is possible to assign these to shopper groups, countries, zip codes, etc. But the site owner wants to assign to site languages. It is important that these methods are not just translations but he needs completely different methods.
Is it possible somehow?
The most advanced shipment plugin that I know is https://open-tools.net/virtuemart/shipping-by-rules.html
Many features and rules for different scenarios so ask them if what you require is possible somehow.