Ancients

Level 10 - 14 vault: G2 green army,  NO MELEE

Level 15 - 19 vault: G3 blue army,  NO MELEE

Level 20 - 24 vault: G4 purple army,  MOUNTED only (no monster dragons)

Level 25 - 29 vault: G5 orange army,  MOUNTED only (no monster dragons)

Level 30 - 34 vault: G6 red army,  NO MOUNTED, NO Beast or Elemental

Level 35 - 39 vault: G7 yellow army,  NO MOUNTED, NO Beast or Elemental

The highest level of vault you can get is determined by your guardsmen and army's colour HAS to match with your vault for your raid to be successful.