The Latin seems quite wrong... e.g. "segmentum pacificus" should actually be "segmentum pacificum" [1] to keep genders correct. Was it the same in the books (which I don't know)?
[1] see Latin dictionary: https://www.online-latin-dictionary.com/latin-dictionary-fle... and https://www.online-latin-dictionary.com/latin-dictionary-fle...
Those words are supposed to be "high gothic" (https://warhammer40k.fandom.com/wiki/High_Gothic) which is definitly inspired by latin but not the same.