Make the Zombie Horse useful and obtainable

The zombie horse should be obtainable in survival, possibly by feeding rotten flesh to a skeleton horse, or having a regular horse killed by a zombie or zombie villager. Instead of having zombie horses just be for show, they should have a purpose, such as being immune or invisible to undead mobs when riding one. you could also zombify a horse and cure it with a weakness potion and golden apple to make it faster, similar to what you do to villagers to make their trades better. they could also spawn like skeleton trap horses, when lightning strikes a horse or donkey, with zombies riding them. zombies are not projectile mobs, though, so maybe zombified piglins with crossbows or pillagers would make more sense. if killed, they would drop rotten flesh instead of leather.