Those two would circle each other like Alley Cats. There would be hissing, spitting, Ashot's haughty "Well my clients were satisfied!" And Dieter's: "Screw their satisfaction, mine paid double, I slapped them, and they paid more!"
There'd be a moment Stephen was sure they'd knife each other... before they'd break down into grins, back slapping, and he'd find them later, drunk as skunks, Ashot hanging upside down from a table, and Dieter under it, snoring. The pair of them having become best friends.