I think each is as important as the other, in fact they can be seen as the three legs of a tripod. It should also be self evident that we should take all sensible precautions to minimise risk to life and limb to ourselves and our audience. We place a great deal of emphases on recreating battles. Obviously, battles in the 17th century were very dangerous places. Therefore we must preserve the illusion of danger, whilst minimising the fact.
Battles are open air plays with a cast of thousands.
If you accept that our sole aim is to teach history, then it follows that we should be accurate. Flippantly, we should aim to be accurate enough to be able to take a fortnight's trip with Dr Who's Tardis Tours to the 1640s and not get spotted as tourists. More practicaly, our way of teaching history should introduce no more misconceptions than any other method. By that, I mean every way of seeing the past carries the danger of misrepresentation, ranging from minor misunderstanding to complete fallacy, and that we should aim to minimise the misconceptions that could be given by our re-enactments. For example, take a c1640s pistol in a museum case.