Armed and dangerous, uh ?
it's better to go with more generals and lesser troops per generals than 2 fully fit generals. if you have 5 generals, you can hit 5 times per round. thus have more chance to destroy his army really fast, eventually in 1 or 2 rounds.
If you have 2 generals and he got 5, it'll need you AT LEAST 3 rounds to kill him. you see the difference in costs, as you get hit 15 times instead of 5 or 10.