The study I read may have used three spine stickle backs along with 10 spine stickle backs. The other minnows that were feed to the pike and perch were prefered to the stickle backs. In one case a perch that had attacked and started to swallow a stickle back began to bleed from the gills, evidently injured by its prey. The perch managed to eat the stickle back anyway.
If someone is looking for forage for thier small bass (4"-10") stickle backs will be more difficult for them to eat. However I am sure that a 16" bass would have little problem eating a 3" stickle back.