Why do my berserk commanders disappear after winning fights

[Illuminated One]

I don't know about consistent, in the hard sense everything can be made consistent, but having some sort of realism that you can relate too is important.
I.e. ok, we have unicorns but everything works the way we're used to makes (maybe) a good unicorn game. But we have unicorns so we are unrealistic anyway so humans reproduce through laying eggs and then throwing the eggs into the wastebin and making children the normal way (what, why eggs then? Rule 7-3i of course) and the law of ant-ropy states that the world will be gradually filled by ropes... I'm still wondering if these mushrooms were edible...

It's unrealistic in the first place to have a rout occur exactly on round 50 (that's about 5 minutes of combat) or any other fixed round for that. Quite simply put why would a soldier who is totally uninjured or fatigued and all his comrades are so too suddenly decide to run away and leave his wife and daughter to demon summoners?
There would be better ways to prevent endless battles (icrease fatigue by 5 on round 50, by 10 by round 75 by 15 by round 100 ..., let an SC rout if he's too worn out and not berserk...). Of course the AI taking over after round 5 and SCs being so strong would be even more of a problem but then you change that...