Final answer:
In 'All Quiet on the Western Front,' the characters Leer, Müller, Kropp, Haie Westhus, and Paul are approximately 19 years old at the beginning of the novel.
Step-by-step explanation:
The question seems to be mixing the characters from Erich Maria Remarque's novel 'All Quiet on the Western Front' with references from other literary works and historical figures, making it somewhat confusing. For clarity, in Remarque's novel, the characters Leer, Müller, Kropp, Haie Westhus, and Paul Bäumer - the protagonist - are all around 19 years old when the story begins, as they are described as having enlisted to fight in World War I shortly after graduating from high school. None of the provided references correspond directly to the novel or provide information on the characters' ages.