Beginner's Luck or Great Strategy - Steemmonster

So I have been in silver ranking for over a month and have gotten use to a specific Life formation for some days now. Trouble started brewing in the past week where I have come up short on the win column with this Life formation. Rather than just blaming myself for being too poor to invest more to level up my form I went a different route. I studied my opponents's formations to determine any weaknesses. After reviewing many of my battles I was surprise that around 50% of my opponents in the ranking range of 1200 - 1600 use these three cards in the formation.

The three cards: Daria, Sea Monster, and Manticore in this exact order were staples in most my opponent's dragon summoner forms. At first glance this looks like a cheap formation as all three cards can be purchased at affordable prices. (Likely cheap now because they are reward cards.) Although when combined together they actually make a very strong combo.

The Sea Monster's high attack and health makes it a solid first position monster and with self-heal it makes its survival rate. Then right behind is the Manticore a solid second position monster with reach and flying. Reach to attack in the same round as first position and flying is good at avoid melee and range attacks from non-flying monsters. To top it off Daria adds +1 melee to both monsters. That makes the Sea Monster attack at (5) and Manitore (2) for a total of (7) melee stat in one turn!

One way to counter is to use magic and high toughness. Check the match below where I used this combo and was defeated by a opponent with a Life splinter counter.

Have anyone encounter this combo more often than not? What is your approach to neutralizing this?