Zombie Survival

It's a balancing factor that is supposed to make escaping to a secure location feasible. If zombies maintained full speed we'd basically have a force that is dumber humans with the ability to exponentially force-recruit and not caring about personal safety. This would be a very short struggle for everyone not physically separated from them at the start. It would be normies vs a growing crowd off their rocker on pcp.

On the other hand if you want to introduce any degree of realism:

1. if it's a disease a vast majority of infected will be dead within a week. Fill your bathtub with water and barricade the door - it's going to be pretty much over by the time you really have to leave.
2. If it's supernatural bs but decomposition still applies see above - you'll be down to facing skeletons
3. In both cases extreme climate is your friend if it doesn't affect you

I dunno.

Even slow movers in bad shape are a problem in numbers.

So, carefully eliminating individuals before they can turn into a horde should be the default.

Once you get enough living together, you fortify and get snipers trained up. Set up on the walls first and pick off anything undead that comes close. Slowly set up an expanding circle of raised emplacements with sniper observers to pick off individuals at a longer distance from the settlement, and give warning for any hordes as well as being able to thin out a horde as it gets closer, and continue depleting the horde if they surround the settlement.

But, for lone travelers, assuming that you have a ranged weapon that's quiet enough, always take them out. You never, ever leave an enemy behind you if you can take them out without causing a worse problem.

I think that's the key to long term zombie survival. You have to take every reasonable opportunity to reduce the spread of the agent that's causing it. Literal walking dead zombies, they're all a disease vector. Every one you put down makes future survival easier. So it's a calculated risk. Measure the risk of your infection in the attempt, measure the risk of attracting any unseen zombies, and if those risks are low to zero, it's going to be a long term benefit to take one out.

Obviously, in a WD scenario, firearms increase the risk significantly compared to quieter weapons. But there are other options available, including the old and trusty Pointy Stick™. Even the roughest spear you can make gives you the reach to make a quick finish to slow zombies 1v1 with very low risk of contact, so you only have to worry about being capable of moving faster if the weapon fails.

Bows can replace firearms at that kind of range, as long as you practice, and it takes the risk down to zero for a single shot, since the noise a miss will make is in a different direction than you.

You're right though, don't fight. Assassinate.