Why is a corvette more than twice as good at piracy suppression than a Nimitz supercarrier?

[Alfray Stryke]

It is represented. There is a speed value you can see in the ship designer and tooltip. It’s what afterburners modify. That being said, your fleets will generally only move as fast as your slowest ship.

Fun fact, there used to be a bug in which fleets would move at the speed of the fastest ship, so you could put a single corvette in a fleet of battleships and they'd all move faster.