Like a true red deck, Animated Army incentivizes playing it aggro but your elementals only activating on your turn makes you particularly vulnerable to returned attacks
Who can really say for sure
Many of the original base keywords are "evergreen" and still used commonly in Magic design as of 2019, such as Flying, First Strike, and Trample
The fact that it costs eight mana also hardly seems like a concern, given how easily green can pull ahead of other colors with land ramp and mana dorks
Making your adversaries discard is awesome, but what if they dont have any cards in hand
Of course, it has to die to do that, which means your opponents have to choose if its worth sacrificing their creatures, being slowly pinged to death, or just biting the bullet and hoping theyre not your target