You make a good point, but I think “lowest risk” is also not the metric either. You could buy 100% bonds and be even safer.

You want some risk-adjusted return metric parameterized by average returns and also volatility.

Judging a pension by how it performs in 2008 seems wrong. Like their main job is to perform well over long periods of time compared to other funds.

Checking this shows that 12 years is longer than 1 year, and thus is a better metric.