I don't know. I'm new but I find these units fun to play with and against. I think they are weak to minions that can move backwards and decent champion scope, but all of you must know this already. I haven't found too much trouble playing against any of these units but I tend to value champions with a lot of scope. Admittedly, however, a lot of my poor samurai have been blasted off the board by annoying rangers at times... But I have still won some of those games.

Obviously, the ability to capture without moving a piece is very strong but I like that these units have a short scope from which to operate. Most of these units have only 2 range at most on their "destroy" abilities, other than VoidMage if I am not mistaken, which IMO is a pretty nice place to be. Trading a Rook for a Ranger++ for instance, is a good trade for the Rook in the early and middlegame, but in the endgame a rook will completely dominate the Ranger++ meaning that the Ranger++ loses a lot of its effectiveness as pieces get traded off.

There's also the case of the AntiMage which nullifies these pieces entirely, right? Maybe I am not seeing something but I don't feel that pieces with destroy abilities are inherently oppressive. Annoying, sure, but not oppressive.