An argument can be composed of more than one premise and each premise can be expressed as a WFF, and then a conclusion (thesis) correctly drawn from the series of premises, although in most cases, these premises are not stated as WFFs or in a formal manner. Few people would enjoy reading a series of premises and conclusions stated in logical form, so generally translation is required for analysis.
One needs, in argumentation, to provide warrants for accepting the truth of each premise. These warrants range from appeals to the veracity of matters of fact to additional chains of premises leading to accepting the original premise as true (which would mean that the first premise in the series was a conclusion of other premises).
Quite often these argumentative chains can be quite long, contain many terms (not all of which are explicitly stated), and require some de-rhetorical reading to bring the argument itself to the forefront. One is reminded of some of those "brain-teasers" where one person never lies and the other never tells the truth, and the reader is presented with a string of statements that will lead to knowing which person is which.
Understanding logic and the various methods and requirements of argumentation, and then making the all premises and conclusions explicit and linked to one another in a logical chain more often then not is enough to show humbug for what it is.