They provided the DB data so your argument for all of those reasons is invalid. They could have easily spent a single sentence providing the CFM data. So no, not a single one of those reasons is valid to omit 6 words.

They made a claim, they didn’t need to mention the power claim, but they did. They should have omitted the claim itself using your logic, instead of the supporting data. The argument is flawed itself.

and we commonly have to accept that a certain presupposed level of knowledge as well as ambiguity is necessary.

Like knowing making a discharge tube longer or shorter affects its aerodynamics….? So we know the claim is false already…? Their ambiguity is meant to mislead people with zero working knowledge of the subject… anyone with any experience will see its flaw immediately.