How are Zapo and Zepo the representation of the same individual although they are two different people?

Zapo and Zepo are described quite similarly in Fernando
Arrabal's play "Picnic in the Battlefield". For once, their uniforms are nearly
identical except Zapo's uniform is a different color from Zepo, who fights in the enemy
lines. Therefore, here we have an ironic way of telling us "birds of a feather": Same
thing, different color.

Secondly, Zapo and Zepo's names are
also nearly identical with the exception of a simple letter which, again, shows that it
is the same thing with a different name: Two typical soldiers, sent to the battlefield,
no clue as to what they are doing in war, none of them is sure why they are each other's
enemies, they are about the same age, and have the same hopes and wishes. They both
represent the ignorant youth sent to fight a bloody battle that they cannot even
identify with.

We also find that Zapo and Zepo do similar
activities, share similar likes, and Zapo's parents are quite taken by him, treating him
like if he were their son as well by inviting him to the picnic. Again, both Zapo and
Zepo represent the huge loss of young men that occurs as a result of war: Young men who
often do not comprehend how dangerous war is, and who idealize it to an extent. Some of
them hardly know what they are doing in the battlefield in the first place. All are just
as innocent, just as unfairly taken, and just as naive. They are one same youth, with
many different uniforms, names, and families.