You balance a game to the PCs you have and the genre you want. Acrobatic heroics in a pulpy action game of BW might be Ob 2; in a grim and gritty war campaign they might be Ob 5. If you want the PCs to be larger than life heroes you make the acceptable intents and the possible consequences of failure match. Pulpy or heroic might be, “Succeed and you kill all ten of them while the Baron stares slackjawed. Fail and you still cut them all down, but the Baron makes his escape in the commotion.” You’re awesome either way. In a grimmer game, there may be no intent that allows victory against ten to one odds. Maybe success is managing to escape yourself and failure is getting disarmed and captured.
Balance is how you set expectations and genre. It’s not a thing in itself. You match it to your game.