Originally Posted by
Cleretic
Yeah, this is absolutely the angle. Tactically, Venat's plan was ironclad (or at least, as ironclad as it could get). Ethically, it was questionable.
To a point on an 'ironclad plan' though, you have to be willing to take the authors' word on it. Actually showing to exact lengths that a plan will be successful--and more successful than any alternatives--would just get tedious and boring, as well as lessening the impact of the actual characters enacting said plan, not to mention being basically catnip to people who value being smarter than the story over enjoying it. You kinda have to accept whatever groundwork the story goes through to confirm 'this is a good plan'.
Emet-Selch specifically saying that Venat's plan worked when his wouldn't have is part of that. Emet-Selch is a trustworthy adjudicator of Plan Goodness here, both as someone who initially opposed it and someone with a uniquely wide amount of knowledge of the situation, so if he says that it's the only one that would've worked then we can safely assume that is indeed true.