Dragoons probably have the worst AI/pathing in the history of video games, Blizzard switched engine view from top-down (as in warcraft 2), to isometric halfway through production, and dragoon collision size is bigger than map squares (rhombuses actually due to view), so their script tries to move them into unoccupied space which is smaller than they are so script moves them again... and again... and again... and then you have to move them across the bridge /cry