How can I get animation diversity with only one Locomotion Behavior?

Getting animation diversity means playing a different set of motions on each characters for the same behavior (e.g different walking styles). The choice for each character is done once at the beginning of the simulation. If what you want to achieve is more closely link to behaviors and you want to be able to dynamically change style, take a look at the related question on this page.

The first thing to do in order to increase animation diversity within the same motion style is to use increase the Randomize Start Offset.

In order to use different motion styles, you need to use  Locomotion Channels on your Motion Clips in order to avoid mixing motions from different style together.