Yes.
But there are three big types of dictators, in those situations.
- Those who say "You do as I say or you leave with your stuff."
- Those who say "You do as I say or you leave naked."
- Those who say "You do as I say or you die."
From what you say, you would be either type 2 or 3.
Type 2 can only work if the exiled is a complete outcast, hated by most of the group, and if the supply level is critically low.
Otherwise, you would always have people asking to give at least some rations, clothes and a weapon.
And refusing this would be looking unecessary cruel, which is the fastest way to be deposed.
Type 3 can only work if people worship you as a godlike figure or if you inspire so much fear in the group that they don't dare to context.
Or if the man you want to kill is a real bastard which deserve death because letting him live would be unfair or dangerous for the rest of the group.
Killing for other reasons a man who could have otherwise just left would just make people hate you.
So before starting to play the "join or die", you would have to be some kind of guru inside your own group.
To the point when people don't care about butchering or enslaving the rest of Humanity.
You would then have to be the same kind of guru for the "newcomers".
Because, long term, they will just try to run away or to revolt when they get more numerous than the members of your original band.
Most of them won't like the idea of being untrusted second class citizens forbidden to travel as they please.
As an individual, faced with the choice to "join or die", I join.
Then I stack up supply and deffect at the first opportunity.
Because the choice is simple :
- Risking my life to survive facing the wild alone and maybe get myself in a very confy position.
OR - Risking my life to survive as a slave around guys who would have killed me without blinking for what I had on my back.