The "legacy" angle is what makes the JSA different than other superteams. Without that, its just the JLA by a different name. Which is what it was until Robin became a member in the 1960s ( sporting one of the worst costumes in history). The "Super-Squad" era helped cement that with the inclusion of Power Girl, the Star Spangled Kid and the Huntress. The 1999 revival was pretty much built around that concept.