[neatoman]

Come to think of it, I know there was a theory that Krang's human disguise would have been Sacks, and the face got changed because of reshoots or something that made Krang unrelated to Sacks. While I doubt that was ever case, mostly because I don't see how the trailer face looks like Fichtner (But you know, recasts...), it would have explained why Sacks had Ooze in the first movie and why Shredder would trust him in the second.