Schwinn in the 80s was completely chaotic; they were trying to survive, and dealing with all sorts of different suppliers and sales strategies. By '83 or so, Super Le Tours were full chromo and butted, but i suspect they had piles of the earlier-style carbon-steel Bridgestone-built Le Tour frames, so they created the "Super" le Tour as a way to move those frames; kind of a "lipstick on a pig" strategy-- The early Le Tours are quality, nice-riding frames but they were heavy and by the late 70s, they lacked significant amounts of curb appeal.... putting nice components on'm probably enhanced the desirability via the bling factor.
When Schwinn got Giant to start building frames for them, they were able to get incredibly nice frames for the price; the quality-to-price ratio was amazing, at the time....