Well, advantages and disadvantages are there.
Let's say khis screwed up my game. And when I finds out he messed up I'll of course be really mad! But look at the bright side. You definitely know you cannot trust him again.
I had lost few important matches due to my work schedules and meetings. Times like that I wished if I can set an assistant manager just to make few changes like arrow up/down or from attacking to defensive or preset style etc.. Allowing limited few options can change a game. I really think this will help a lot of managers..

Oh and I do not wish to share my fb credentials as its personal.