This issue is of the same type which I have mentioned in several places in my books, that the Arabs sometimes mention a single number of something, but by that number they do not intend to negate more than that.

Sayyiduna Miswar bin Makhramah رضي الله عنه and Marwan bin Hakam رضي الله عنه narrate that the Messenger of Allah set out in the year of Hudaybiyyah to visit the Sacred House (for Umrah), and he did not intend to fight. He took seventy camels with him for sacrifice, and the number of people was seven hundred, thus each camel was for ten people as a sacrifice. In the narration of Sayyiduna Jabir رضي الله عنه, it is mentioned that the number of Companions who participated in Hudaybiyyah was fourteen hundred.