User blog comment:Тостер/Scraping the Bottom of the Rogues Gallery, Part 1: Introduction and Whatever Left From The List/@comment-27700324-20161024014516/@comment-3423279-20161024192016

Pretty much all of Smallville was operating under the "before they are renowned heroes" or "before he was actually Superman"

That would be difficult to do if they were all wearing the outfits of their future, more well-known selves.

Plus, they basically were using prototype costumes from the start.