Based on the specific example (hashing buckets for a hash map/table)… just use a hashing function that uses a random seed per map/table instance during hashing

Based on the specific example (hashing buckets for a hash map/table)… just use a hashing function that uses a random seed per map/table instance during hashing to prevent insertion attacks, eg. SipHash. This prevents an attacker from being able to purposely engineer the overloading of a single bucket with too many entries, allowing the implementer to use a standard linked list per bucket without worrying about external influences. Then, if you're still worried about the one in a trillion chance that a single bucket receives too many entries… yeah, you're over-engineering and wasting your own time, and the mental capacity of every developer who comes after you to try and understand your attempts to circumvent the problem in supposedly "smarter" ways.