This mechanic reflects how a small group of rats may not be an issue, but a massive swarm of hostile rats could overwhelm creatures they normally couldn't on their own
(Targeting opponents, anything they control, and/or cards in their graveyards is a crime.) Lazav copies exactly what was printed on the original card and nothing else
Judge, who, as a certified financial planner, spends his days steering clients away from exactly this kind of thinking, is more measured but arrives at a similar place
Jarads Orders Jarad's Orders fetches two creatures, one to the hand and one to the graveyard, for 1 mana less than Shared Summons
I also am considering putting either Valkyrie Harbinger or Kalonian Hydra into this deck, but I do not wish for this deck to be too similar to any of my other decks, so I would prefer to avoid putting those cards into this deck, if I can avoid doing so, and I also am not yet certain about Doubling Season, staff of completion, or Selvala, Explorer Returned, since those cards would be awesome in this deck, but I do not wish to use them in every deck in which they would be a good addition
But the mythic enchantment goes further than that, scaling up our sweepers and allowing for surprise lethal from Chandra tokens or Purphoross Intervention