Horizontal power structures help prevent autocratic systems from arising by limiting the available power to any one person.
By making the nominal selectorate, the real selectorate and the winning coalition one in the same the system must act in the best interests of everyone.
This forces the output of nothing but public goods that people want and need.
Selectorate theory indirectly points to the solution of power. In the dictators handbook they state that in workplaces making them democratic would solve a lot of problems. I agree.
It also solves a lot of political problems to increase the democratic nature of the system. Make the power structure more horizontal. Basically the solution indirectly points to anarcho-socialism
If the nominal selectorate, the real selectorate and the winning coalition are one in the same for a political system, the system is completely horizontal. This is anarchism.
If the nominal selectorate, the real selectorate and the winning coalition are one in the same for a business. This is socialism.