Subverted: Robert and Charles trade a few attacks, but Robert realizes he's not getting anywhere and begins focusing more on dodging entirely.
Double Subverted: Eventually the fight carries them into confined quarters and they are forced to go blade-to-blade in an attempt to overpower each other.
Robert's sword breaks in the middle of the fight... and he continues blocking Charles with the hilt.
Robert's mentor explains that "if you actually hit someone in a swordfight, you're doing it wrong!"
Zig Zagged: Both men start of flynning until one of them is injured in which case, he keeps away until his Healing Factor can take care of the wound. He comes back and starts flynning again and is injured a second time with the same result.
Averted: Robert and Charles do occasionally clash swords, but it only makes up a small portion of the fight.
Enforced: "We don't want the actors to get hurt. Just have them hit their swords against each other until the end."
Lampshaded: "Try hitting someplace other than his sword!"
Robert and Charles, both master swordsmen in a tournament where they're unknown, flynning through their qualifying match to make everyone else underestimate them and ensure they both go on to the later battles.
They are in a strange fencing sport which involves trying to knock your opponent's sword out of his hands by hitting it as hard as you can. This involves a lot of swords clanging together.
Exploited: Charles has to deliver a message, and Robert has orders to thwart him. Being Genre Savvy about the lighthearted setting, Charles resorts to a lengthy and mobile Flynning duel with Robert, which sees him arrive at his destination and deliver the letter while still fighting.