It might be. Narrative is great and all, but sometimes you need a visual comprehension of the situation. So no Commander, you can't stop the vampire from leaving the cave, but you can stop him from leaving the camp. The ferals would die in about five minutes from the sunlight exposure, so you have to survive a five minutes if you don't want to fight them. And considering that they're not getting any stronger the longer they stay out, you'd win a battle of attrition against them.