When you're a kid playing Little League, it seems the best player on the team is always at shortstop; that's because the shortstop sees more action than any other position and requires the widest range of skills. As you get older, the best shortstop from Little League stays there, while others find new positions. The best overall are guys good enough to stick at short through high school and college -- and then get a chance to play there as a pro.
To make a long story short, shortstop is the toughest position to play on the diamond. (As you'll often hear scouting directors say about a good young shortstop with questions about his defense, "We'll let him stay there until he proves he can't." That's because the hardest thing to find is a shortstop who can hit.) And if you're one of the greatest to ever play the position, it means you're a uniquely talented player who deserves to be in the Hall of Fame. Ergo, both Alan Trammell and Barry Larkin should be enshrined in Cooperstown.