I get the excitement behind doing a pre-origin show like Gotham or Smallville. But I think it puts interesting limitations that the showrunners are unwilling to abide by. They want to set the show before the hero exists, so we can see the buildup to that heroic introduction.
It does not seem to long before they start bringing important characters or heavies that will populate the hero’s future. Gotham has given themselves a bit of breathing room, with characters who are rising in power, but conceivably become something more of a problem down the road.
But it gets silly if you have Superman fighting all his villains before he is Superman…or more frustrating, Jim Gordon dealing with all of Batman’s villains before Batman exists. And it just does not seem to take pre-origin shows very long to start falling for this trap. Often by the second season (if not the first) they are introducing key characters that really ought not be appearing quite yet.