How do I add and delete units from a nation?

[Sombre]

The problem is that coming up with a list of 6 alternative heroes is difficult for some nations, and I couldn't really think of heroes that I could give to Hinnom that fit the theme among the list of national heroes. I suppose I can create heroes out of scratch, but that really is beyond my capacities at this point

Just remake their current heroes without the pop eating. Simple.