The first time I did it, I just did whatever because all the other tiers were so simple that no thought was required. I lost and realized "Oh, so they aren't playing around then...." and then I tried again, choosing slightly more sensible targets, and won without an issue.
Still, proving that a person can play the game and win under fixed circumstances doesn't necessarily mean that some events are not poorly balanced. One glance at the "Recommended" gear levels for certain events will demonstrate this. No amount of strategy/game-play skill that doesn't have "and great RNG" as a defining factor will win some of these events without being excessively geared beyond the recommendations.
I'm not sure if the people responsible for events simply do not understand what suitable recommendations are, or if they're purposefully setting the recommendations low to convince me I'm bad at this game and should upgrade my stuff (conveniently, it immediately gives you the option to do so after every failed attempt).