With tiny creatures and tokens being cornerstones of white mana since the very beginning of Magic, Mentor of the Meek has been a staple card ever since it was first printed in Innistrad
As far as I can tell you'll not often have multiple Armies on your side (though it is possible), even though - to me anyway - "Army" smells go-wide rather than go-tall
Then when you want you can flash it back for another Treasure and another trigger for your artifacts or sorceries
What was supposed to be a readily available set that a player could grab 2 packs of, mix together, and play against a friend who had done the same became an incredibly scarce product targeted by scalpers
Include this aura with already beastly Eldrazi like Kozilek, Butcher of Truth, or just conscript one of your many other creatures
It's the grim calm before the storm, when loyal partners share the quiet resolve to press on