If you talk to fire department "extraction" staff, or EMT's, the answer is clear as day that CTD's are a joke in the first place cause everyone is different. Especially the little ones.
I've taken wrecks apart. I'll spare you stories.
Here's the current list of CTD's in use by NHTSA:
Look at the height weight mix, there's serious reality issues.
Note that all of this is for auto makers to figure out the least expensive way to build safety stuff into a vehicle.
https://www.nhtsa.gov/nhtsas-crash-test-dummies