Here's a fun analogy. Suppose you sample two versions of the same dinner, each prepared by a different chef. The dinner on plate A tastes much, much better to you than the dinner on plate B. It's just not even close. Should you conclude on that basis alone that the ingredients used to make the dinner on plate A were superior to those used to make the dinner on plate B? Of course not. Perhaps, for example, the chef who prepared the dinner on plate A actually had inferior ingredients, but is just the vastly superior chef.
In the very same way, one shouldn't conclude that a recruiting class was good solely because the team is good a few years down the road.
Edit made for clarification