Just got my 10th shard and I wanted to share some observations.
TLDR: I think there is a weekly cap of ~2 shards
I farmed exclusively Shadowsilk Burrower’s and Wood Webbers. I had 3 shards when I started and I found I would get 1 every hour with about 300 kills per hour (~.5% drop rate). I would get 2 and then spend the rest of the day farming and get no more for a long time (days.)
I dropped my farming down to an hour a day before bed and I got 2 shards in an hour again. So I go nuts and try farming for hour to get nothing. I tried the rares after hitting a wall for a week and I get one more shard. The next Saturday I clear my schedule, put on Phil Dragash’s Return of the King audio book and spend the next 20 hours farming the last 4. Two dropped before the end of the first chapter and I am hyped. 5000 kills and 10 hours later I did not get another one and gave up for the day.
8/10 was string me in the face and the rest of the week I put in many shorter sessions and I was convinced that there was something limiting the drop rate. Lost of people post things like “I farm 20 hours, and then, 2 drop in 30 minuets.”
So I waited a week (real time no reset) and Set out to send another Saturday farming the 2.
47 minuets later I got the last two.