Does size matter?

Does size matter? When "playing someone else" (acting), I believe it does in a lot of cases, such as when playing Beowulf. Of course, not having lived during that time period, I can only take a stab at what I believe someone who lived as Beowulf would be built like.

While he lived with, though not actually recognized as, nobility, not having a cut physique wouldn't bother me in the slightest. In fact, I'd expect him to be on the heavy side.

But, Beowulf left the bosom of that family and, we're led to believe, lived a hard and, oft times, brutal life. History has taught us that living type of life would not only necessitate his being more slender and muscular, it would lead very naturally to it.

It bothers me every time Kiran Bew's scenes as Beowulf when Bew is clearly not at his best, especially since Bew is not incapable of having a more slender/muscular build (see http://www.imdb.com/media/rm3599409664/nm1240908?ref_=nmmi_mi_all_pbl_36)

So, bottom line, in the case of Beowulf, size really DOES matter (to me.)