Santa’s elves all look the same.
They’re clones, grown in birth tanks in a lab under Santa’s workshops.
They’re poured out, dried off, injected with memory-rich protein bases, and sent through automated speed-training to learn the skills necessary to make toys.
When they’re ready, they join the assembly lines to make toys.
There’s always openings available, because clones only last a few years.
Eventually they wear out, or get injured or maimed, and they’re harvested for their memories, and pulped into a nutrient fluid.
Which is then piped to the birth tanks, where a new batch of elves are growing.