its a weak authentication. if you use a dog for work/husbandry, law military, it does two things.

1] regionally unfamiliar language, dog will obey your commands, but not commands of regional language.

2] parrallel handling, different dogs trained in different languages dont step on each others task,in response to the same cue command.

e.g. left dog, sprech im ze deutsch - right dog, govorite po russki