How can they make Troy without Cassandra?

[Estilicon]

@Melandry

Yes, the Odyssey contains the famous description (from the section where Telemachus, Odysseus’ son, is visiting Helen and Menelaus at home after the war) of Helen walking around the Trojan Horse imitating the voices of the wives of the men inside to try and rile them up (for what purpose is unclear). However, astorian is correct that the account of the Trojan Horse in the Aeneid is the most complete and famous in ancient literature.

Well, Virgil wrote his poem 800 years later than Homer. He was able to use hundreds of years worth of legends about that ancient war.