You send 200 fighters and 60 get killed. In the same situation, if you send 20, what do you expect would happen? (I mean, you won't lose 60...)

It's like the Bill Hicks bit about the number of losses in Desert Storm. Iraqi casualties: 20,000 - 50,000. US casualties: 147. "Does that mean if we sent 148 guys we still would have won?"

Depends. If the 20 are more spread out and your enemy is using inaccurate weapons, then maybe more would survive.