To a point, but in general the idea of "establishing facts" is not terribly current in ancient history. To limit ourselves just to the literary evidence (that is, written material transmitted directly from the ancient world rather than recovered through archaeology) the body of evidence is so small that any time somebody uses it for something significant (that is, something more complex than "the battle of Gettysburg happened") they will justify it. If I ran across a work casually saying, for example, that Nero set fire to Rome without justification than that would cloud the entire work for me. Likewise, I heavily use a source called "The Periplus of The Erythraen Sea", a merchant's handbook to the Indian Ocean. Literally every person who is in my topic of study has read this work, yet I am including a couple pages justifying my use of it. Likewise, there is a half page of Greek called the "Muziris Papyrus", a fragmentary loan agreement, that everyone has read and I need to include a few pages on my interpretation of. The limitations of the evidence means that any audience will me largely familiar with much of the available evidence.

That being said, the largest difference between ancient and modern historians is not the evidence we use but the questions we ask of it.