Well, as I promised - a fieldtest were done.
It wasn't game breaking in my opinion, and in opninion of my opponents. But to be truly honest - I weren't try to do something ridiculous and just tried to play in my advantage.
All tests was on Patrol level.
First three games with Greathorn, Howl and Hakar, seven Masks and five Ashmens. There was pretty long moves for Greathorn - for 8" and for 12" - making hime a much more mobile treat that lurked behind Masks front and ocasionly nuking specialists, leaders and unfortunate infantry.
But much more useful were bonus moves for Masks combined with Howls Inspire - you no longer worry about one Mask breaking the line because her mate can follow her! And it was no less useful to move Ashmans i contact with enemy so the can (at last!) gain benefits from their Hakar Inspire!
Two secong games were with same setup, but with two Longhorns instead of Greathorn. Why not give a try to a mass forced disengagement? So I did and it was glorious - so much control over enemy and so much battle-movement that eve Goritsi were awed. Also it really helped with Stad your Ground motivation when my Ashmens moved closer, so the could activate, Interact and dart back with markers on them for my opponent frustration, that was tarpitted by everlatching Masks.
My conclusion - it is a good Trainig as it is. The movement shenanigans any way will not be able at first turns - because there is no contact with enemy at that points. And then it happening pretty ocasionly and in limited way - towards enemy, wich pretty comparable and even much less, the Goritsis mobility.