And maybe you should think about what you are trying to accomplish with a strike. Are you trying to do damage, or set up a throw and/or lock?
Karate styles do some increadible damage with their way of striking. They hit and retract and whatever physics that control the way whips do damage also come into play. Bujinkan tends to not pull back the striking limb, but use it to do more damage to the guy once it hits the target.
Honestly, I do not want to appear to be saying that I am some sort of expert, but the overall approach to combat determines everything that takes place in a competent art like the Bujinkan from strikes to throws to the way it deals with weapons. To try to take one aspect like this without dealing with the big picture is... complicated in my experience. But of course, I still have so much to learn.