Well, Ninko was assigned as a LB, which is NOT is natural position. He would get killed covering slot receivers or TEs. He is NOT a LB. Only this year is when someone, thankfully, put him in as a DE. Since that switch, he has been disruptive, abeit not a JJWatt, but, pretty decent.
So, sometimes having a player be able to play various positions just does not work. In Ninko's case, DE is where he belongs.