Arnold in a sense is all genetics. If he were shorter, in bodybuilding he would have been a poor man's Franco Columbu, winning maybe 1 or 2 Olympias if even that (height was more important in bodybuilding back then, no way he could have beaten Zane or Oliva with shorter stature). This might have affected his movie career, but he could have still been succesfull with tricks a la Stallone. Height is the most important factor in politics (shows you how seriously you should take politics). If he were say 5'6, 5'7 there is NO WAY he could have gotten far in politics, yes height is so important.
So, with a change of only one physical characteristic, you could essentially destroy his career and life.