Liam Hemsworth (Sgt. Kinney) is the real-life brother of Luke Hemsworth (Sgt. Abell). Luke previously appeared together with his brother Chris Hemsworth in Thor: Ragnarok (2017) and Thor: Love and Thunder (2022), so only Liam and Chris have not yet made a movie together.
Russell Crowe (Capt. Eddie 'Reaper' Grimm) has been in movies with all three Hemsworth brothers: with Liam Hemsworth (Sgt. Kinney) in Poker Face (2022) and Land of Bad; with Luke Hemsworth in Thor: Love and Thunder (2022) and Land of Bad; and with Chris Hemsworth in Thor: Love and Thunder.
The four main actors are all Australian
Despite being an American film, with an American director, American studio, and a cast of American characters, Milo Ventimiglia is the odd one out as the only American actor in the lead cast. All other actors are Australian or British.