The phrase "as fallacious" is correct and usable in written English.
It can be used when comparing something to a fallacy or indicating that something is misleading or deceptive in reasoning.
Example: "The argument presented by the opposing side is as fallacious as the one we debunked last week."
Alternatives: "equally misleading" or "just as erroneous".
In the wake of many examples and discussions of this sort, contemporary accounts of fallacies widely recognize there are arguments which have the form of traditional fallacies, but cannot be rejected as fallacious.
So the conventional wisdom about how we have to fear a Chinese bond-buying strike just doesn't make sense — and in fact it falls down in exactly the same way as fallacious arguments about the harm done by fiscal deficits in a depressed economy; basically, Erskine Bowles is making the same error as whatshisname.
The idealistic view that for these items to be is to be perceived is rejected as fallacious.
That was found to be as fallacious as the nonexistent weapons of mass destruction.
It will not surprise you to hear that I think his arguments are as fallacious as his conclusion.
The idea that robots will teach people to relate to others, she says, is as fallacious as the argument that e-mail facilitates telephone conversation and then direct discussions.
Of course, as has been discussed since the 1970's, the idea of the gallery-as-white cube is fallacious.
Further difficulties with second-order epsilon terms surfaced, and it quickly became apparent that the proof as it stood was fallacious.
Detailed refutations to creationist claims that are out of scientific context and thus fallacious could be treated as counter-fallacies.
The idea that Britain will lose economically by not expanding its role as a air travel hub is fallacious.
The idea that the role of Frederick Douglass wasn't afforded an historical fit in the film, as some have intimated, is utterly fallacious.
