Age of Sigmar/Tactics/Edition 1.2/Kharadron Overlords
Post GHB 2017
Changes in the 2017 Generals Handbook release and subsequent FAQ have somewhat changed the working of many of the core "power" units in the army.
Khemists have lost the ability to stack their +1 attack and -1 attack powers, and have had a 40% points increase. Though still very much the core of the workings of the army, they are no longer "OP", and list building now leans towards potentially buying another unit of arkanauts or thunderers instead of a second/ third Khemist.
Probably the biggest change, they can no longer all take the same special weapon, and instead, each of their choices are now one per unit (although they can all still take an option each). This prevents taking large units of cannons and gaining a Khemist buff to smash face. Also the range of the mortar has dropped from 36" to 12" bizarrely.