Farmed fist of crota four four days when it first started dropping. Got one and leveled it. The next day got 2 more on other chars without trying. Yesterday a friend of mine got her 6th without trying. Turns out it makes no difference since there's only a .02% chance of the crux dropping. Also since I've now had 8 ce hm drops across my three chars and I've gotten total 6 energy and 3 shards.