It seems like the only way you could get a turn three double striking Edgewright with the Piston sledge equipped is
1) Plains, Memnite, (Memnite, Signal Pest, or Vault Skirge)
2) Plains, Edgewright, (Memnite, Signal Pest, or Vault Skirge)
3) Plains, Piston Sledge, sacrifice an artifact to...