I mean... It's literally part of the plot I made, so while you can disagree with the story, it's not as if you know what messing up would actually be. This chapter accomplished what I wanted it to accomplish in terms of moving the plot forward, developing relationships, etc, so it's quite successful in both my opinion and in the opinion of the people who actually support me. I actually chuckled when reading what you wrote, so you've earned a comprehensive response for your troubles.
If you expect the MC to do no wrong and always solve every problem perfectly (which you shouldn't, especially since you're apparently a LiL fan), then sure, maybe that Gary Stu MC could solve it. However, do you seriously think that the MC in PoP could have come up with exactly the right words/tactics to negotiate with a person/civilization that he has ~0 information about, has more information about his people than he has, has things he wants, wants nothing he has, and actively dislikes his people, all while he has exactly zero experience negotiating anything besides the price of a sack of flour?
Just because the MC does something wrong or, in this case, is a risky gamble doesn't mean "the author messed up". It means you aren't thinking critically about the story or characters and are under a false assumption that the MC is somehow perfect. Spoiler alert: he's not. The MC will make mistakes, will try and fail, and will never be the best at everything. That goes for every character. I firmly believe in making characters realistic, which means that they won't always be right, that they'll make mistakes, and that they may not do the "optimal" thing that we, as a reader, may want them do. It's their failings that make their successes all the better and, frankly, having flaws is how readers/players actually empathize with these characters.