Palamon and Arcite have to decide who gets Emily in armed combat, which means that the better fighter gets the girl. Or does it? See, Palamon and Arcite are both equally strong knights who are able to marshal equally strong armies when necessary. This means that in addition to strength and skill, luck (a.k.a. having the gods on your side) is necessary in order to win. The knight's job is to bring his talents to the table and hope that the gods will do the rest.
This isn't to say that strength and skill are totally without use in "The Knight's Tale." Theseus demonstrates how might can be used to make right when he goes to battle with Creon to avenge the mourning women. And as the tale pauses to describe the battle-array and sheer spectacle of Team Palamon versus Team Arcite, we can't help but be kind of impressed by it all.
"The Knight's Tale" portrays a world in which military strength takes you only so far; something more than this is necessary in order to be successful.
In "The Knight's Tale," physical force is the only effective manner of resolving disputes and enforcing rules.