You are forgetting the fact you lose less CS per man when you have less men. If you have 10 men, you maintain over 90% of your CS. At 50, you are down to 50%. At 100, you are down to 40% due to diminishing return. That is why it is wise to have multiple small militia units than 1 large one most of the time.
Having 38 nobles leading 30 men each is much better than 11 people leading 100 men each.
