All the three poems mentioned above are similar in themes. All those have wars, inhuman killings and futility of war in the core. So, in a broader sense, the three poems are anti-war poems. But still they are not quite the same and cannot be categorized so in a stricter way.
 
The poem Dulce et Decorum Est by Owen raises a perfect war against war through its ironical use of the Latin phrase in the title. It centres around the horrific warfare in the First World War. The main message in The Eve of Waterloo has probably been the transitory existence of happiness in human life — how laughter, love and chivalry turn into tears and sighs. And the last poem ‘Five Ways to Kill a Man’ interestingly vows to tell us some ways of inhuman killing. But it ends up criticizing a war-ridden and poverty-stricken twentieth century world where people are already dying bit by bit out of poverty, joblessness, illiteracy, communal disharmony, terrorism and so on. 
 
While ‘The Eve of Waterloo’ and ‘Dulce et Decorum Est’ are more conventional in their style and form, ‘Five Ways to Kill a Man’, originally published in 1990, is rather modern. It does not concentrate on things like rhyme schemes or poetic devices, but does on the striking way of presenting the theme in a satirical tone.