Thanks to the assistance of another collector, one of my many theories has been confirmed.
Most of the time, when a kid is mint-in-box, the outfit factory and the kid factory match. (For details visit HERE.) However, there are some exceptions.
Recently, we determined that AX factory clothing came on IC kids. For these kids, the outfit tag and the kid’s tag would not match.
There were several other factories in Taiwan, but the only one other produced dolls, the UT factory. I speculated that AX outfits may also have come on UT kids. However, until this past week, I had no proof.
Thanks to Melissa W., I now have that proof. She was able to confirm that her MIB UT kid did come with an AX outfit. This discovery was accidentally serendipitous!
So, we now have proof that AX outfits came packaged separately AND on IC and UT kids. This goes a long way to explaining why IC and UT clothing is so difficult to find.
Unfortunately, I do not think we have any way of knowing what percentage of IC and UT kids came with AX outfits.
Some of the other Taiwanese factories produced specialty outfits for the All Stars series (HRS), Sports Collection (CY, FD), and the Western Wear Kids (CY). Like the AX outfits, these outfits normally came on IC kids. Of the remaining Taiwan factories, the only other factory that may have provided outfits for boxed kids would be WW, but my gut says it did not. So far, there is no indication that WW outfits came on kids.
Can you prove me wrong?
Update (April 2021)
I was proven wrong! (read above) I now have proof that regular CPK outfits from Taiwan factories other than IC and UT came on these kids. This includes AX, UT, WW, and HP. This goes a long way toward explaining why there are so few IC outfits and so many IC kids!