Though Bestigor are now a Special slot with pretty much nothing going for them.
Abilities like this though really are going to push the whole “not taking a banner on most units” trend going on. Unless 8th as rumoured does something to promote usage of banners.
In essence you only give a banner to a unit you are not expecting to be going to do any loosing anyway. Bestigors aren’t good enough to beat those units.
I’d think most CD units would suffer from the same problem.