Fire: tank, stealth, stealth, snipe, snipe, ooze / heal
Green: tank, block, support, heal, support, block
Life: tank, heal, shield, shield, stealth, arrow
Death: tank, off tank, block, snipe, snipe, flying
Water: Bronze/silver just spam magic / ruler of the seas and you get to gold league. I don't play water in gold so... Dunno.
Tank = Cerberus, flesh golem, paladin, haunted spirit... a meat shield that fits your mana without getting in the way of the rest of your formation. Hydra is also good.
Stealth = Stealth attack monsters, like Feral Spirit and Elven Cutthroat.
Snipe = Snipe monsters, like Centaur and Twisted Jester.
Ooze = Glittering ooze.
Heal = Monsters with "Tank Heal", like wood Nymph and Beetle Queen.
Block = A tanky ranged monster you can use against Splash attacks and snipers, like Wood Elemental and Undead Priest.
Shield = Monsters that provide other monsters with Armor bonuses, like the Armorsmith and Defender of Truth.
Arrow = Strong ranged monster, like the Air Elemental or Peacebringer.
Off tank = Monster with Reach, like the Spineback Wolf or Corrupted Pegasus.
Flying = Monster with flying like the Dark Enchantress, Phantom Soldier or Fallen Specter.
Non-pro tip: You can use a specific splinter's formations in a different splinter more easily if you use a 2-mana (epic) summoner while trying.
Meant to be posted on 