I don’t know why blizzard didn’t came up with this earlier…but.
All those demons share one big flaw, when you summon them, you are no longer in control of their actions. They might attack your current target - sure, but if you quickly need to switch them to other target game doesn’t provide you with tools for that.
Simple and elegant solution should be like this:
while those demons are active, their summon abilities will work as attack commands.
This will allow demonologist to controll his demons without adding additional command spells in game.
This is how thoughtful class gameplay design should look.
In the other hand i would prefer that you simply reverted demonology back to the MoP/WoD and never touched it again… but we - warlock community has to deal with crap that you came up in legion.
Have a nice day