>The incentives are against a fair evaluation: the reviewers have the incentive to overly criticize others so that they can stand out more.

Wouldn't that(how you view and fit in with your team) be part of your review? If I was Bob's manager and all reviews he gave of his teammates were "Teammate M is a dumbass and the only reason they are productive is because I do 80% of their job for them", wouldn't leave me thinking Bob is great. It would leave me thinking Bob is a jerk who doesn't work well with others.