No, in my view MS and factual evidence would be wholly unrelated to interpretation. What I read today and my interpretation would be far removed from the interpretation of, for example, the Church Fathers. Each interprets the Bible in his/her own way, depending on personality, background, schooling and internal/external influences. Polycarp was killed for his faith, one of many. I would never dishonor a martyr by questioning his existence. This according to one of my sources:
The martyrdom of Polycarp, in 155 or 156, was an example of mob violence, to which Hadrian had been opposed. The occasion was the festival of the Commune Asiae, a notable anniversary of Caesar - worship of which Smyrna was a chief centre. There is good reason to suppose that the crowd, stirred by the ceremonies turned against the Christians as known opponents of the imperial cult, and the Asiarch, Philip, having tried in vain to induce the bishop to acknowledge Caesar as Lord, condoned the action of the mob by ordering Polycarp's execution.
The account according to Eusebius, a solid and reliable Church historian: The Early Christian Church by J. G. Davies. A lot of information there to write off as mere legend. In a court of law that would have gone down as a "reliable witness," with time, place and an accurate description of events.