@Roopehun I don't think people's jealousy is the root of their questions. I think it has to do with the fact that a pretty severely under powered fleet (sorry there @Waqui, but that's some weak sauce) was able to best the challenge while others who have devoted significantly more resources were not able to. Couple this with what could be construed as the poster's condescension about it led to that reaction. Telling people who have tried something hundreds of times and failed that it was 'easy' is certain to elicit some hard feelings.
While I don't doubt that Waqui's alt obtained the sixth star, I can't reconcile exactly how he did it with that fleet. Perhaps the trick isn't in the fleet he posted, but in the fact that he upgraded the fleet during the challenge. Maybe there's something to it. Maybe there's an adaptive difficulty to the challenge that's set based on when you enter the challenge each time it shows up, and instead of upgrading in between challenges, we need to upgrade during the challenge so that difficulty doesn't reset.
And @Waqui - nobody said unlimited reinforcements, they said zero cooldown, which I can personally attest to - three turns in a row for me.