I use to only do NM CB (Nightmare Clanboss) and the clan that I was in rarely killed  it = 1 NM CB chest a day

That satisfied me for the  longest time as about once a month I would snag a  yellow sacred shard

Many told  me UNM CB was so much better. It was  not until I finally ended  up in a clan that downed  both NM and UNM CB daily that I began to realise what everyone  has  been telling me all along

From my experience 5 Sacred shards a month is normal and compared to my previous game experiences / well I have  been missing out  on a lot

So my advice to all new  players is get in a clan and start hitting NM and UNM CB as soon as possible to improve your account