I’ve read, researched, and written extensively on the topic of Biblical chronology. My writings on the topic are not simplistic. I have a rather complex proposed solution to the question of the date of the census and the role of Quirinius. I’ve studied Finegan (perhaps the foremost Biblical chronologist of the 20th century), Vardaman, Kokkinos, and others on the topic. I’ve had discussions with Vardaman on the topic of Quirinius.
However, I also adhere to the teaching of the Church that nothing asserted as true by Scripture can be false. This has been definitively taught by the Magisterium; it is not an open question. And believing what the Magisterium definitively teaches is not fundamentalist or simplistic.
As for the idea that this passage or that is a type of literature and therefore can contain false assertions or fictional details:
“But it is absolutely wrong and forbidden, either to narrow inspiration to certain parts only of Holy Scripture, or to admit that the sacred writer has erred.” (Pope Leo XIII, Providentissimus Deus, n. 20).
One cannot narrow inspiration or inerrancy to only those parts of Scripture which are one type of literature versus another.
“Divine inspiration extends to every part of the Bible without the slightest exception, and that no error can occur in the inspired text…” (Pope Benedict XV, Spiritus Paraclitus, n.21)
Infancy narrative literature (if such a thing exists) does not constitute an exception to Divine inspiration.
“…they put forward again the opinion, already often condemned, which asserts that immunity from error extends only to those parts of the Bible that treat of God or of moral and religious matters.” (Pope Pius XII, Humani Generis, n. 22).
Similarly false is any suggestion that immunity from error extends only to those parts of the Bible that are not one type of literature or another.
Pope Pius X published a Syllabus of Errors, in which he condemned the idea that “Divine inspiration does not extend to all of Sacred Scriptures so that it renders its parts, each and every one, free from every error.” (Lamentabili Sane, n. 11).
Again, saying that falsehoods can be found in Scripture because a passage is a type of literature is contradictory to the teaching that each and every part of Scripture is without error.
“everything asserted by the inspired authors or sacred writers must be held to be asserted by the Holy Spirit” (Vatican II, Dei Verbum, n. 11)
The Holy Spirit cannot assert an error or a falsehood, because God is Truth.