All four troops have water link for +9 mana from each blue match. Since The Silent One takes 18 mana to fill, and the team gets +25 water mastery, he is likely to fill on the first turn with a mana surge. Even without a mana surge, he can still be filled on the second turn.
After TSO silences himself, Templar takes over. Unfortunately, he takes 10 mana to fill and requires a mana surge or brown to fill. The main benefit to Templar is wiping reds off the board, since that is the only type missing. He also fills Druid with green and provides armor for the team. If TSO gets wiped out from skulls, his armored trait and armor gain make him a good tank.
Once you have adequate armor, and wiped the enemy’s armor with a couple Druid casts, Shadow Hunter will snipe the highest life enemies. Also, her agile trait provides even more skull defense in case the enemy gets through both TSO and armored Templar.
Finally, Druid finishes off the weakened enemies. With the fast trait, being double fed greens by Templar, as well as leftover blue, he still sees plenty of action even being in the last slot.