When i was GM on pre-beta and i was summoning elder zards on the roofs! xD and all people tries to get Boxes xD and Nino summoning PA Ninos or Caterpies lvl 3000 x)
I said Mission #7 is too hard because Crystal Onix and Red Gyarados aren't in spawn yet... and i think legendaries should be implemented to the game but not in spawns, they should be implemented in the game at raids or events (At least legendary birds).
You're right there, maybe the balance is...