Copolymer is introduced as 'the greatest storyteller in the world', and patently is not. He tells Teppic the story of the Tsortean War, including such classic storytelling as "Wossname's armour shone like shining armour. Fight and a half, that fight. Between thingy, not the one with the limp, the one with red hair..."
Strangely enough, Copolymer's fellow Philosophers seem to hear his stories as the superb, ground-breaking epics they are undoubtedly intended as. This perception is not shared by Endos, who had a faint glimmer of pain behind his eyes when Teppic mentioned how Endos must have Listened to Copolymer many times.
The Roundworld referent is presumably Homer, whose storytelling has lasted forever - and, not incidentally, writes of a war between rival nation-states started by the theft of a woman. Copolymer's full version of the story of the Tsortean war, by the way, is brilliant - a perfect combination of epic epithets, like 'red hair' and so on, with the sort of oral storytelling that more often happens among drunken friends in a modern context. It also includes all sorts of little details from the real Trojan cycle, thrown in with everything else, like Copolymer's reference to 'the one with the limp' (which might be Philoctetes; 'Oedipus' also means lame, but he isn't part of the Trojan War cycle) who 'didn't want to go, said he was mad' (that was Odysseus).
The word copolymer means a polymer derived from two (or more) monomeric species, as opposed to a homopolymer where only one monomer is used.