Cameron White

You only need a single source animation clip for the original sequence, and you can then use the clip properties SOP to create a few virtual clips from the different frame ranges.
I've attached a simple example that slices up an idle to walk sequence into an idle and walk loop that can be used in the crowd solver

If you don't want to do the editing ahead of time, the Agent Clip Properties SOP can be used to create several named regions from a long source animation clip

You can use the Agent Clip Layer DOP [www.sidefx.com] for that.