well just like today a good grappler can shut down a boxers weapons.
But a boxer who can wrestle can shut down the wrestlers attempt to impose his phase of combat (ground) by mastering the clinch phase of combat.
From what i understand Pankration is not a martial art at all really , sort of like MMA. Its a sport with a collections of styles. Many cities had specialties. Some cities had fighters well known for their nasty submissions. Some cities were much more striker oriented. They all wrestled, and boxed. Pankration was just about doing everything else as well.
That qoute does sound familiar, if i find it i will post it here.
I do know that there is this story of a fighter in the Pankration which i think tells us they were well versed in all manner of submissions..
V. For example, you have heard of the Cilician pancratic athlete, whom our fathers called "Halter", how small he was, indeed much smaller than his opponents.
PH. I am certainly aware of him, in view of his statues, for bronze ones stand in many places.
V. He possessed excellence in skill and courage, and harmony of body made him very strong. When the young man arrived at this sanctuary (he sailed directly to Delphi for the trial of strength) he asked Protesilaos how he might overcome his rivals. He said. "By being trampled upon". Faintheartedness immediately seized the athlete, as if he had been struck down by the oracle. After he first discovered the heel maneuver during a contest, he later realized that the oracle ordered him not to let go of the opponent's foot. For the one who wrestles with the heel must be trampled upon repeatedly and lie under his opponent. By doing so, the athlete gained and illustrious name for himself and was defeated by noone.
Heroikos by Philostratus