Plutarch and Pliny were learned. I see not even a single piece of ancient source material even mentioned in Luke. He seems ignorant of many of Paul's theological positions, including his views on justification. The first thing we are taught as historians is not to trust any source. And all these distortions find their way into all ancient sources, secular or otherwise.
Physical evidence is also essential to the reliabality of many historical claims.
Certainly, if amazing recoveries happened in the temples of a pagan god, there can be nothing divine about the same thing happening in the presence of a Jewish holy man. And if we can be told about giant ants by Herodotus, who treats this tall tale as if it were true, then the tall tale of the zombies in Matthew should not surprise us either. The same things can be said of every aspect of the gospel accounts, in Luke or otherwise. I have been asked if physical evidence is really all that important, and the answer is often yes. If there is a reason to doubt the reality of a person, it is generally doubted without physical evidence.