Great find - I would also say that you could use them as redirectors, flee from charges and reform at the start of the next turn if needed. Could intentionally move into "bad positions" to get flank charged, only to get free movement and a reform!
Definitely all about the boost to mobility being converted into linehammer. Stubborn makes it a lock, but I think have a champion in a non-Stubborn unit might help you preserve Unit Strength to get the FBIGO.
