It was good to know it was a potion, though frightening that a potion could go so far. The imperius curse only worked on a one by one basis, and it controlled actions only, not thoughts. The person cursed was aware of the situation. The potion was widespread - the entire nation. The Death Eaters were strong, but they would lose eventually. If everyone were out from under the potion, they would lose even faster, but there were so many risks of high death tolls at that. Kingsley knew they needed to win, but the fewer the deaths the better. Violence and revenge would only prolong the effects Death Eaters had. Revenge didn't help - only justice.
"If you know and can talk of it," Kingsley disliked that Terrence was held back, upon pain of death, of speaking about many things, "How exactly does the Mark compel people? Is it tied into the magic in the tattoo, or is it something we could replicate somehow?" Terrence was a good fighter, and if it were possible to put him to better use, Kingsley would rather do so. If not, well, then they only had two people to move potion-ed people with, and that was that.
Kingsley did agree that controlling them be a backup plan, but it was an important one. Best case scenarios were difficult to come by under the best of times. And they did not have the best of times. He honestly laughed at Terrence's suggestion, not for it being silly. Bloody hell, it was generally good. But if Terrence knew him, he would have understood.
"You don't need the staff off the potion for it to be out there," Kingsley pointed out, "And I've sniffed out most of the staff to make sure." It had taken effort and time, but he had. "If people have analytical minds and read the paper on a regular basis, it's there, as clear as day. The writers don't even realize it, but it's there." He leaned forward a little, "I could show you sometime, if you don't believe me or want to anyway. I've been reading the patterns since before the first war. I suppose, though, that could be why I see it. And your point does still stand."