Indeed. I have played a good number of them (although there aren't enough people around to play with to get really good at more than one or two), and all the variations require slightly different strategy. Changing the board size by one unit, or the number or arrangement of starting pieces, can totally shift the balance of the game, explaining the complementary changes to things like who moves first, whether the king can participate in captures, and whether the corners or the whole sides are winning spaces.

A serious omission from the article (although I suppose understandable, given how the article is focused) is how the inherent asymmetry is accounted for; usually, games are played either in two rounds, switching sides (so you have to learn to be good at both halves to win the full game), or by first betting on how many moves you think it will take you to win- lowest bet plays white and loses if they run out of moves.

I object to the casual description of Hnefatafl being similar to chess- it's a two-player strategy game played on a board, but it's no more similar to chess than checkers is. Chess players (while they might have an advantage in strategic thinking over the average person) in my experience have usually found that their chess skills don't transfer at all.