after one week of insomnia because of my newest baby, I had some time to improve my pathfinder:
- smoother animation due to modified unit loop (okay, it is not sensible on these screenshots, sorry)
- basic follow-the-leader behaviour that resulted in better FPS, and much better terrain bottle-neck passage behaviour (the upper groups are just slightly scattered after passing the narrow area in the middle - it was a pain for them before).

I think this follow-the leaders feature will be the basis of formation control, so after scattered state the group can be reformed again hopefully