I like the idea of new cavalry units with a cheaper AP cost and being a sort of assault units however I'm not sure that with these stats they would be any cheap and with unbreakable ability they are gonna be more expensive than a standard cavalry unit in terms of AP.
In our chat talks I was more excited to suggest some eagles to elves instead of dire wolves but it's only a matter of choices, also I believe these new kind of cavalry units should be easily breakable with little damage to make em a cheaper choice to chase fleeing enemy units or to flank with a fast unit