Double tapping - so bludgeoning corpses is cool, but double tapping should be implimented. A faster, albeit louder method of ensuring a corpse never re animates. The benefits of this being that you can destroy a large number of corpses quickly. The negatives being: Its louder and draws more attention. If your perception is bad you can shoot yourself in the leg or the foot or miss entirely.
Zombie types - Specifically more of them.
Zombie squirrel/rabbit - Do not spawn at world gen. Spawn if a squirrel/rabbit corpse is not butchered or bludgeoned. Faster than zombie dogs. Minor damage. Pretty Harmless unless in swarms.
Zombie deer/moose - Same spawn rules as the squirrels/rabbits. Slightly slower than zombie dogs faster than average zombies. Slightly weaker than zombie dogs.
Zombie wolves/coyotes - Same spawn rules still. As fast as zombie dogs, more damage.
Zombie gasbags - Like boomers but filled with a flammable gas. Explode if taken out with a gun. Deflate harmlessly if attacked with melee. Leave a cloud of explosive gas that explodes if touched by fire.