Elves gets absolutely shredded by Walking Ballista, and also loses to other decks just being faster / more disruptive. Elf ball is like a turn 3 or later deck that gets pushed even further in the face of disruption/bad draws.
I think the card is way more interesting if there is an application outside of Elves.
I'm unclear if that paradigm holds up. If elves gets a reasonable hand and start on the play, shops basically has to resolve the ballista turn one to kill any enabler or elves could snowball in one turn. Even without Glimpse it is not unreasonable for an elf list to put down 2 lords and be out of range.
Yes it's a good tool but since green is already Shops natural predator I think they are very well positioned after sideboarding as well to just ruin that decks day.