Consensus is obviously preferable. But it scales very poorly. A simple workaround is to nominate someone as the tie-breaker. To avoid secondary rounds of nonsense, you try to pick someone with the respect of their peers.
Holocracy actually doesn't use consensus. The mechanism in Holocracy for decision making can be summarized as "do whatever you think is right to fulfill your stated role. No consensus nessesary. If the way your doing thing is actively preventing someone from fulfilling their role, then you two work it out (through a strict mediation process) but other people's opinion of what you should do is irrelevant (i.e. No consensous). Only the roles directly effected have to agree." Consensous seeking usually descends in to hypotheticals, theory, and butt covering. far better, according to Holocracy to just let people animate their assigned roles however they think is best.
If reward and punishment are tied to individual judgement, everything descends into hypotheticals, theory, and butt covering.
Consensus is nice because it's a relative of shared understanding. When it can't be achieved, trying to achieve it still increases shared understanding. Having a tie-breaker is the only role you need in small groups.