The organisms that might be affected include Leader(Zombie、zombified_piglin、zombie_villager、Drowned、husk)。

The Difficulty is set to hard, with a chance to summon a Leader (Zombie)，The Leader (Zombie) has a higher maximum health value, which is easy to distinguish, and apply this command to it.。

/attribute @e[type=minecraft:zombie,distance=..1,limit=1] minecraft:zombie.spawn_reinforcements base set 0

Setting the spawn_reinforcements attribute of Leader (Zombie) to 0 will still trigger reinforcements.