Except in games where interpersonal politics, by design, play a decisive role, this is undesirable.
The nonparticipant's strength is at least 3, so they are guaranteed to win the second round of combat, and the entire contest.
Of course the argument can be made that this means the winner, chosen by the kingmaker, played with the additional restriction of not annoying the other players as much, presumably a more difficult task.
However, this is often seen as undesirable because it conflicts with the concept that the strongest few are allowed to proceed to the next round.
[3] Wehrle used these ideas in several of his designs, including Root, John Company, and Oath.