Probably the most realistic in what would happen (remember is the early 1800s)

So according to the lore, the normal zombies have been decaying for little months to even 10 years, which explains why they are slow and look so decayed
Runners are said to have been infected by just less than a few weeks, not months, explaining their great speed and mobility
And what happens in game makes is realistic as in the very early 1800s with ongoing war and the only true survivors being soldiers with weapons makes more sense than civilians

Interesting