The Sequence Layers' command is such a handy assistant to manage multiple layers . It's also a great way to get multiple footage items sequenced .
Select the layers you want to sequence by selecting one, and then shift clicking or Cmd+clicking (Ctrl+clicking) on other layers to select them. The first layer you selected remains in its initial time position and the other layers will move to new positions in the timeline, depending on the order in which you selected them.
Choose Animation>Keyframe Assistant>Sequence Layers.