All styles of play are viable. If anything, Smithing + Sword + heavy armour is pretty overpowered, and less interesting than ninjaing as a whole as you have less 'fun stuff' to do rather than mining an area with runes, assassinating people with a bow then slitting their throats once they blunder near you.
nb: this technique doesn't work against elder dragons. Fffffuuuuuuuuuu