Well, I'm not sure 8 direction behavior would be the easiest way to achieve this with. Is there a reason for 8 direction?
I would probably try to do this with either the Pin behavior, making the sprites simply orbit the node without any particular behavior, or you can try out tanoshimi's for an easy life hack
The reason I chose 8 directional is because the rotational behavior is only meant to be temporary. So, the units are created and rotate only as a visual behavior but when they are given orders they stop rotating and move towards the commanded checkpoint using 8 directional movement. If they should park on a new node, I wanted them to rotate again though..