To clarify some points, I am referring to CLDR based coalition orders.Which would be one type of sort order for a language, but is based on the language’s code and the data in the CLDR package. CLDR is a seperate data set from the Unicode character set, but is also made available via the Unicode Consortium website. See: http://userguide.icu-project.org/collation
Poking my head around this issue I see that there is a GoLang Module for using CLDR language taged data. see: https://godoc.org/golang.org/x/text/collate
I understand @bep 's hesitation to reinvent what should be written and provided via GoLang. To add some specification for what should (IMO) be accessible to Hugo users would be to sort some range (like a set of taxonomies, or a series of posts) by a defined language collation order per a given CLDR tag. This would be an attribute of a specified sorting process and would not necessarily be the same as the language specified in the params of the hugo website… something like the following hierarchy.
Sort by the CLDR specification for a given language tag on the unique sorting operation as specified {{else if}} sort by the language specified by the default website language tag {{ else }} Sort by the language of the rendering computer