I've gotten those gauntlets a couple times. Honestly I have to say don't waste your time just farming them, wait until it's the Nightfall then grind for them. Strike loot drops SO MUCH MORE OFTEN in the Nightfall. I set out to grind for the Arc Flayer Mantle last night, decided to just solo it a couple times since my buddy got 2 of the mantles out of our 3 runs and I got 2 Treads Upon Stars in the same 3 runs. First try, got the Arc Mantle. I've gotten the Darkblade Helm, Baron's Ambition, those gauntlets, a lot of that Strike loot just from Nightfalls. Trust me just wait until then. I'm anxiously awaiting the next time the Saber Strike is up, I REALLY want that Warlock helmet...