The last trial to undertake at the grounds is the Chieftain’s Hunting Trial. This time you have to destroy 6 large machines: 2 Scorchers for the first wave, 2 Freeze Bellowbacks for the second, and 2 Frostclaws for the last.
You should pretty much be able to use your Blast Sling effectively against the Scorchers, but it might be a good idea to try and knock off their Mine Launchers, too. We say this because, for the second wave, taking a Mine Launcher with you against the Bellowbacks will take them out in mere minutes! Aloy may move slow carrying such a heavy weapon, but she’ll make up for it in fast and hard-hitting damage for the second wave.
Going against Frostclaws always seems like a dreaded idea, but if you can keep your distance during the last round you should be able to take them out just as easily as the Scorchers with your Blast Sling again. They may get the upper hand on you which, if that’s the case, do the usual hit-and-run method until you can turn the tables back around.
Using this method should increase your chances of completing the trial in anywhere under 5 minutes! Once done, head back to the Keeper for your rewards.