Hi, posted this in answers but thought I’d post it here as well.
I have roughly 20 models with different joint chains, but with exactly the same animation clip data (e.g. the clip ‘Walk’ is between frame 20 - 48 on all of them, etc.). Each model has like 60 animations. Is there any way for me to copy the animation clip data from one model to another so I don’t have to type in the 60 animations 20 times?
Cheers!
If the bones (that are animated) are the same name, orientation, length and scale - there is a process to copy the data from one bone to another in the generic rig setup. But - I do not know this method (I think it is some code/script). Research for that.
Otherwise with the different bone chains - the animation data can still be copied from one rig to the other in humanoid rig setup, as long as the proper avatar mask is used to copy over the humanoid bone data.
The ‘extra’ bones animations, outside of the humanoid structure will need to be masked and animated via animation layers set to additive.
This is something to keep in mind - to plan for - prior to creating 20 models with 60+ animations - on future projects. 
Thanks for the reply, I see I should have thought this over more properly before. Anyhow, a few cups of coffee and some good music and I got it done in a couple of hours.