If youre able to combine it with more defensive opportunities, or one that will increase your hand in a very short period of time, it can be well worth bringing out, but its unlikely to stay in play for long
Army of Allah can only get you so far, and the buff this card provides is needed for a deck that still struggles (even more so without the inclusion of Fallen Empires)
Theros: Beyond Death introduced new, mythical heroes rendered as elaborate constellations that spanned the full length of the card
The benefit here is that you control the card flow
But when you can be casting creature after creature that draw you cards, ramp you lands, and remove problems from the board, the fact that this relies on combat damage just gets to be kind of a nuisance
The idea to use eldrazi came from an early playtest where Faerie Artisans created a copy of It That Betrays, to the owners dismay