The core difference between nimble and slow teams is their relationship to uncertainty.
In slow teams, there is intolerance for uncertainty. Success is a lack of failure. Uncertainty is seen as a risk to success. The priority is on the illusion of predictability through approved roles, rules, plans, agendas and goals. This culture of approval is what keeps slow teams risk-averse, reactive and slow to respond.
Nimble teams see uncertainty as inevitable and vital for growth. Success is growing together. The priority is on freedom to define the good we care about together and to engage each other's goodness in realizing the good we seek. This freedom is what gives nimble teams their velocity, alignment and agility.