Based on the myth "The Wrath of Achilles," what are four reasons why the Greeks won the war against the Trojans?

The student's question does not specify any particular text, although one could logically presume that Homer's The Iliad provides the basis of the inquiry. The classic text tells the story of the ten-year war between a coalition of Greek kingdoms and the Kingdom of Troy, lead by King Priam. Priam's son, Paris, of course, takes Helen, the beautiful wife of King Menalaus, for himself. The Greeks retaliate by attacking and laying siege to Troy. During the course of the ten-year conflict, many well-known figures from Greek mythology appear and play prominent roles, including mortals and immortals alike. The Iliad, alone, however, may be insufficient to provide a full response on the Greek victory over Troy. Other sources of Greek mythology must also be consulted.
The question asks for four reasons the Greeks prevailed over Troy. The most direct answer as to why, or how the Greeks prevailed is the successful use of deception involving a giant wooden horse. As students of the Trojan war know, the Greeks, despite their long siege of Troy, had been unable to penetrate the king's fortress walls. The giant wooden horse was the brainchild of Odysseus (the hero of Homer's other well-known classic The Odyssey) and was constructed with the aid of Athena and Epeius, a respected carpenter. It was hollow inside, allowing for the concealment of a number of Greek soldiers. The horse was inscribed to the Trojans as a monument to Athena and is presented as a gift. Despite the misgivings of some Trojans, the wooden horse was wheeled inside the fortress walls. The Greek soldiers sneak out of the horse in the darkness of night and proceed to slaughter and/or rape all those within the fortress walls.
The "Trojan Horse," in effect, is the main reason for the Greek victory. It does not, however, answer the student's question. That answer, perhaps, can best be formulated by drawing on the recommendations of Helenus, brother of Paris and a seer who Odysseus and other Greeks interrogated in an effort at attaining valuable intelligence on the Trojan enemy. The lessons taken away from this interrogation are that, in order to defeat Troy, the Greeks must meet several conditions: they must enlist the son of Achilles, Neoptolemus, in their fight; they must retrieve and transport to Troy the bones of Pelops, whose grandson, Agamemnon, was among the most powerful of the Greek leaders; they need to bring into the battle Philoctetes, a master archer who would use the the weapons of Hercules in the battle against the Trojans and who had been abandoned by the rest of the Greeks on the island of Lemnos; and the Greeks would have to capture the Palladium, a wooden statue crafted by Athena in the image of Pallus, the god of war. 
The four tasks prophesied by Helenus were executed by Odysseus and Diomedes. It was the wooden horse, however, that sealed Troy's fate while revolting all those upset by the vengeful slaughter carried out by the Greek soldiers who had been hidden in the hollow structure.
https://ryanfb.github.io/loebolus-data/L170N.pdf