Hmm, kinda forgotten a lot of textual evidence from ransom, but I'll give it a shot:
Contention: While Ransom is a novel about overcoming the constrictive traditional bounds of role, the success/triumph they achieve is only temporary in the face of impeding death and destruction
Para 1: Priam
Subverts expectations
freed from his obligations
however, knows he and his city will perish
demonstrates the relative insignificance of such an action in the context of war
Para 2: Achilles
freed from guilt/rage
acts finally as a man - reconnection with childhood
triumph is the return of him as a 'man'
however, he is destined to die on the plains
demonstrates that while triumph can save one from pain etc. they are still subject to fate
Para 3: Humanity (draw on broader ideas)
Achilles' restoration, Priam's new found humanity
Triumph is the result of positive action which can lead to transformation
allows achilles to make peace with Patroclus' death
allows priam to understand fatherhood and common emotions
while triumph may be relatively insignificant in the lifespan of particular individuals, its power arises from the ability to help find humanity
That's a very rough plan of an approach you could take, there are ovbiously several others. It's not overly sophisticated and whatnot, I forgot a lot of last semester's ideas

Remember to try and briefly reference The Iliad if you can (shows research/understanding) and dicuss what ideas Malouf is really trying to demonstrate to the reader.