There are two British paratrooper squads in the game.
They generally use British voicelines but their “commander” in the plane only speaks American, despite British voiceover having the appropriate files.
The “British” paratrooper commander voicelines are actually identical to American, but even when I change the British ones, the squads still keep using the American commander voiceover.
And here is the link to the bug report, which obviously no one cares about over there.
https://community.gaijin.net/issues/p/enlisted/i/mSwP0SpPgjL4