Biblical Scholars often describe the Gospel writers as "theologians", which is somewhat anachronistic, just to begin with. But even if we call them 'amateur theologians' who charged themselves with explaining the teachings of [and about] their Lord, I still don't think God-logic was ever their primary purpose in writing. Not only do the writers constantly embed truth in action and action in truth, but the notion and practice of separating "history" from "theology" is highly acadamized and took centuries to develop. In that respect, such an approach to the Gospels seems anachronistic in the extreme.
I think the Gospel writers were simply amateur biographers, whose material was both historical and Jesus (God) centered. They made no theoretical distinction between things Jesus said and things Jesus did. They made no practical distinction in reporting on the natural and supernatural elements of their testimonies. If we accept the seemingly fantastic events as plausible and consider them to be true, then I think we have to see the Gospel writers as normal people who took up these ambitious writing projects essentially with the mindset and consciences of regular folks. They would naturally have cared about being accurate in the details they included.
Therefore, any suggestion that they deliberately falsified parts of their narratives in order to more effectively illustrate some particular principles of spiritual truth is an insult - not only to those writers, but to the notion of truthfulness itself. Their claim is always to report what had actually happened.
Now then, comparisons of the Synoptics certainly reveal creative arrangement of some relatively contextless content (most notably Matthew's mid-section and Luke's 'travelogue'). Sometimes, certain semi-redundant material seems to have been cut (such as one of two Nazareth homecomings and one of two seaside recruitments). Also, thematic elements were sometimes considered when including or omitting things in order to make a particular point (John clearly knows the story about Jesus' baptism but omits the audible voice of God in order to emphasize the spiritual voice of God). On top of all this, the Gospels were inherently self-serving. That is, they were composed in loyal service to the Jesus movement. However, if anyone on Earth is capable of honesty, then "self-definition" does not automatically imply false or untrustworthy testimony. (* You there, BW? See, I bought it and skimmed it. Am I being unfair? ;) *)
So yes, creative compositions they certainly are, but since when did creativity ever require deception or pure invention? The bottom line is that nothing prevents us from trusting them, and further, from trusting their details to be accurate. The Gospels include more than enough specific details [which show no apparent symbolism or ulterior motive at work] to convince us the writers valued and cared about facts for facts' sake. That is, of course, unless you suppose they were complete con-men. So take your pick. ;-)
PS: For an example of a disputed detail, let's take the rooster incident. It's possible someone was wrong about how many times the rooster crowed, but I really don't care. Two times, three times, 2*3 times? Somebody else can defend that if they want to and/or refine their definition of 'inerrancy' - which I would probably be willing to sign, if I ever bothered or cared to actually read it, and if I ever felt like signing such things, which I generally don't. ;-)
My own point is simply that, any way you slice it, those numbers show the writers cared about detail. I'm sure there's some way to explain the difference, but again, I'm really not worried about it. So I'll faithfully suspend judgment on the crowing count, thankyewverymuch, and take every claim that is clear in its rendering to have happened, historically. :-)