(!) Spoiler Alert (!) -- [Any Details Provided are Subject to Change] (Part 1)

Because the other troops sometimes will “miss” the devour and have a lesser body that is much more “killable” in a proper set of moves. Despite the glitch with skulls spam a troop that can remove another troop with 100% chance, even on a single cast, and also receive the life, attack and armor of the destroyed troop is insanely strong.
“Oh, but i can lure the A.I with skulls.”

  • Yep, and if the trait triggers you are even more screwed.

“But even with three troops you can still manage to win the battle.”

  • Sure, but you are facing a much bigger threat, the stronger the lost troop was the stronger will be the enemy’s Maw, and with any luck cascade things will scalate into a onslaught easily because you will have to handle a bigger Maw while the A.I can keep collecting mana because it still have other three playable troops.

“You can counter Maw, with your own Maw”

  • More proof that Devour as mechanic is plainly broken… If the best you can do to beat it is join the club then something is clearly wrong.

My approach to limit devouring enemies to 50% bonus, IMHO, would help to keep more diversity in teams, Maw would still work well when you use it because you can still remove a key/troublesome troop and get a boost to Maw’s raw status. It would just not be so prevalent in almost every team composition of anyone who has this troop.