- Allow player to recruit characters in his base through own building. These characters would require resources to be recruited of course.
- Player would then have to chose if this new person should be soldier or scientist or mechanic.
- add Engineers and Scientists class of characters.
- Scientists would be needed for research (each lab would accept few scientists (let say 4) each scientist could then provide 25% increase in research (so each fully staffed lab would give 2 research points)
- Engineers would work same way for manufacturing items/vehicles/buildings
Overall, having more characters means player would need to gather more resources to progress, and would have more to lose if his base is attacked (unarmed scientist and mechanics)