More than once in a duel, I've found myself in a situation where a hundred and a half of those fat guys stun the enemy, pushing them back on the initiative scale, without taking any damage in return, which significantly increases the duration of their happy, well-fed lives.
I remember how I defeated battle griffins with armored knights and fat guys, and I was lucky with the stun – they only managed to bite the knights once, so their rage and endless counterattack were completely useless.
Hmm, if I had used zealots and redshirts, it would have cost me much more.