The guy sitting in the tower in Buenos Aires or Sao Paulo will speak Spanish or “Portagee”, Pilots rarely converse with pilots of other flights. “Over the ocean” controllers? Yes, Oakland Oceanic Control covers a vast part of the Pacific but when you approach Japan you are talking to Fukuoka Control and he is a Japanese with limited English skills. Have you been there? I have. Also, I have flown 25 hour flights with 2 air to air refuelings..I know what tired is. Of course I was in my 20’s then.
I’ve been over Japan several times, but not as a pilot or not in the cockpit; only as a passenger.