Have to agree with Bowldancer, this would be a nerf to the meta build of Slayer; a class that, while incredibly useful, is still pretty underplayed, according to what data we have.
(don't see a lot of order melee balls rolling around either, do you? lol, more like SW balls

All to make a niche spec (small scale) more viable? Idk. Order's losing enough cities as is. If you take from slayer, you should give somewhere else. Like wargrimnir said: some classes are more optimal than others. On order, not so many optimal classes.