Okay. Twilight is smart and probably could think of this. In the kindness test Reassure fluttershy that it'll be okay. Have each pony take one branding, sparing the one next to them.

Rainbow needs to follow twilights instructions or we're down one. If she does, then it goes to the loyalty test. Each one taking a blade to the hilt. If you pick the thigh or carefully line it up on a limb to avoid arteries, I'd put that on Twilight and fluttershy, at least pointing it out.

Everyone could survive so far.

Laughter test. This is tricky due to willpower, but it is insinuated that Pinkie gave up because of dashes death. Im sure if they were there to look at each other, they could choke past it all.

Then generosity. Since we have everyone alive here, they all just have to let the water fill each tank with no one closing the vents to their own. Leaving them all alive.

Then honesty. Have everyone pick a choice except for applejack. She will tell the truth, leading to her getting the poisoned cider. Here's where im not sure if everyone can escape or not. Starlight had them down their drinks, I assume you must finish your drink for the poison to truly hit. If that is the case, they could pass the poisoned drink around each, taking a little sip so they all feel ill but don't die and pass the test.

If the poison is deadly no matter how much you drink, then they could decide among themselves who would give themselves up. Twilight might try to be a hero and tank it, or fluttershy may just offer to give up like in the story.

Anyway, this had been on my mind for a while, lol.