Not at all an expert, but here’s my shot at Discipline:
T1) Rambasa + Bird’s Nest
T2) Sparring Partner + Entangling Vines
T3) Young Lightning Dragon + Training Grounds
T4) Young Lightning Dragon + Focus Master
T5) Earthquake + Earthquake
Strategy: Get Rook and Grave out with an early Heroes Hall. Use Rook in Squad Lead to protect your stuff and send in birds to peck at tech buildings. At Tech II, get YLD’s out and boost them to take out tech buildings. Earthquake should help you close out the game.