Что-то вроде?
... : MonoBehaviour
{
public enum Type {Grass1=1, Tree1, Tree2};
public enum Density {Grass1 = 1, Tree1 = 2};
public enum Life {Grass1 = 3000, Tree1 = 20000};
public static ... Create(string ...name, Type type, Density density, Life life )
{
var myNew... = new GameObject(...name).AddComponent<...>();
myNew....thisDensity = density;
myNew....thisType = type;
myNew....thisLife = life;
}
void Start()
{
}
}