I think the 4-H rules have changed over time and perhaps vary by state. When I was in 4-H 50 years ago, all of us owned our own horses and of course, did all our own work. These days, a lot of animals are leased and/or boarded so care really varies. In CT, 4-Hers have to keep records of the time they spend with their animal projects, breaking it down by category such as grooming, training, feeding, etc. As an example, we just had an "Open Barn" here tonight where the kids could work with their project animals and participate in stall cleaning, feeding,etc. Once the time changes, we are not sure if we will be able to continue the Open Barns once a week. In reality, our kids are young (oldest non-special needs members just turned 13) and pretty inexperienced, so the amount of "training" of the horses that they do is limited. But they do help out - under supervision - with stall cleaning and feeding. Of course, an experienced 18 or 19 year old member could potentially be doing a lot of the work and training. That is one reason that I don't see how how a rule change would work... in some cases a 4-Her COULD be giving the AOTE unfair advantage, if they were clipping, etc.
Now the rule here for 4-H Fairs is that the members are supposed to do all the "fitting" which for minis would included clipping, and they do have to do ALL the handling of the horses at the show. Only a few of our members were experienced enough for that this year, and even so, I did the clipping because I had a Pinto show the week before. I told the member to tell the judge she did not do the clipping, that the horse was already clipped, but she did the rest of the "fitting".
I am OK with leaving the rule the way it is, as I made my choice and picked 4-H over AOTE. But it does worry me that someone else might choose AOTE, and that would be a shame.