why not let them scale inot late with a no-crit built?
If they take smite in lane and rush devourer, they will be on a serious disadvantage till it's finally stacked, which needs a long time even if they poach Krugs or Gromp whenever it's up, so devourer gives a strong delayed powerspike and a great lategame(not better than a crit built though) as tradeoff for a poor early-mid.
If they go jungling, they are vulnerable early, don't bring huge gank pressure and they lack the gold they usually need to scale up, so devourer beeing powerfull is just a nice trade of for there otherewise rather weak jungle that might actually allow them to be viable as junglers if the teamcomp supports it.(kayle and teemo probably more so)