It's one of the best adventure/buddy flick films made so these observations are somewhat picky.
The films chief strong point imho is undoubtedly Rudyard Kiping's boys own story, supported by the exotic backdrop of Morocco. There's also an effective chemistry between Caine and Connery as the two soldiers of fortune - I can't see Gable and Bogart bettering their portrayal, and another proposed twosome of Redford and Newman might have made the film detrimentally jovial. Some may also say that Caine's narration is unnecessary and obtrusive, but he gives a presence of Kiplng over proceedings.
On the flipside, we are supposed to feel some fondness towards Caine and Connery yet their imperialist behaviour and cultural ignorance would sit uneasily with some in the age of political correctness - but that's countered by the films cautionary finale. Huston reportedly had financing difficulties so I have no idea if the finished film is parallel to what he originally intended 25 years earlier when first planning to capture Kiping's story on film.