The motif on it is the same as on a seal found in the Mycenaean grave circle with "Agamemnon's Mask" (dated 16th century BCE, centuries too early to be Homer's Agamemnon): https://www.alamy.com/battling-warriors-on-a-gold-seal-from-...
But the Minoans almost never produced goods for themselves depicting warfare until after the Mycenaean take over ~1450 BCE, after these seals were made.
While Minoan princes were often depicted nearly nude and with long hair and sometimes leaping, the Griffin warrior grave was for an actual warrior and among the items he was buried with was a comb for hair.
Just who were the warriors depicted across centuries and different locations in these Mycenaean seals, and what was the nature of their battle?
You can see in the Pylos combat agate that the long haired warrior is fighting above the body of another fallen comrade.
While the motif predates any possible historic Trojan War by centuries, I suspect that the tradition behind this scene is what eventually inspired Homer's story of Achilles fighting Hector after the death of Patroclus, reworked into the narrative of Troy with the original story lost to the ages in lieu of these seals left behind.
Should the Griffin warrior grave in the palace of Nestor turn out to be closer in time to the Mycenaean grave circle (dating off pottery isn't always the most reliable), I'd like to think that the Griffin warrior IS the warrior from the seal, with his greatest accomplishment immortalized in one of the finest works of art in that time, and that we have indeed found the grave of Achilles (or the inspiration thereof), just outside the timeline of various events compressed into a single fiction by 'Homer' and the oral tradition which survived the Greek Dark Ages.