Other mistake: Macrinus and one of his high-ranking friends are discussing Lucilla's son, who disappeared when Commodus died. The guy says that Lucius disappeared when he was "about 12," but in the original Gladiator, he was barely about to turn 8. They also say these events happened 16 years prior, but, again according to the movie lore (without even looking at history), he died in 180 AD, and this movie is set in 200 AD.
Gladiator II (2024)
1 other mistake
Directed by: Ridley Scott
Starring: Denzel Washington, Connie Nielsen, Pedro Pascal
Factual error: The Numidians defend their city against the Roman invaders using also trebuchets - a type of siege equipment that would only appear in the Middle Ages.
Lucius: Strength and honor.