For example, one idea I have heard is to allow smaller community banks to opt into a simpler set of risk-weighted capital requirements in exchange for a higher minimum required ratio than under the more risk-sensitive, but more complicated, standardized risk-weighted requirements finalized in 2013.
A second factor is that everyone taking part in the simulation knew that the scenario involved an economic recovery, by assumption. They could factor that into their modelling. But in a real recession, there always comes a point at which many people are not confident of recovery, and that affects their behaviour.