I think if I boil down my original post it comes down to questioning this.
Is the use of force always win-lose (or even lose-lose)? Can it be win-win?
And come to think of this, I remember a podcast in which Stefan said as much. It was along the lines: if the person that is forced (for example a child) can be assumed to later appreciate that he/she was forced (for example brushing your teeth), then the use of force was justified.
So there are win-win situations even if force is used.
If these kind of win-win situations exist, then it is at least possible that forced leadership might have had a beneficial effect on the fitness of a group. And that this might have found a place in the gene.
I like your observation that:
Which seems to suggest that the time were forced compliance was useful has passed.
Today, yes probably.
But not necessarily in the past. Two groups that never interacted may have had quite different futures. To the extend that one group, possibly with perfect ethics, starved to death while another group in similar circumstances but through the use of force was able to survive. An easy example would be failed crops followed by certain starvation. A group that would without remorse kill the weaker members might survive while a group in which the use of force was unthinkable might all have died.
I know that this is a very unpopular lifeboat scenario, but that does not make it less true. And I suspect that in a time where human population was scattered and rarely had contact this kind of scenario's might have happened a lot. Often enough to leave an imprint on the gene.
May this is the reason why sociopaths exist.