About the "flow field" video.

Ive use an approach like this in my old Wasteland RTS already.

Its basically just a way of unit-to-unit avoidance on low distances.
Its nothing "new". And not even part of pathfinding. But
part of dynamic close-range unitdynamics.
(its basically an additional avoidance vector added
to movement, calculated by the discance of two
collisioncircles, and defined by an exponetially growing
strength of the force the closer the units get)

Its also something you might not even want in an RTS.

Games like Age of Empires and Starcraft tried to be rigid on purpose.
(blocking the path of the enemy in a predictable manner)


BTW: if you have an RTS with hundrets of units, and want to
use a fast pathfinding, use something like a
"flood fill topography" map, starting at the
destination points.

If all units have the same destination, they can all use the
same Map to navigate, no matter where they stand right now.