John's hoping he can surprise Gladio's mates, in turn. Noctis, certainly. Prompto's prowess with guns is of particular interest, purely from a base competitive standpoint. The Guide might enjoy getting up close and personal like he is with Gladio, but he's well aware that he's most effective at a relative distance.

Blades aren't what John has in mind just at the moment while he has the advantage. Instead, he bounces up with the intent of headbutting Gladio beneath the chin. If he's lucky, he'll manage to stun the other man and might be able to get his weapon out of his hands before the Sentinel regains his wits and simply bats the Guide away... or crushes John to his body and holds him tight and squirming there until he's forced to concede.