Maybe it's because of the fact that Earth Splinter have two strong summoners which are Mylor Crawling and Scarred Llama Mage OR the fact that I don't have enough cards on my earth deck which makes me lose much when using the said splinter. Just earlier today, it took me 22 games in total to finish my earth daily quest. I'm trying to be better at it though by slowly buying earth cards and renting multiple earth monsters and summoners.
ign: @rayver0329