I show AMHA and AMHR, I have shown at Nationals and World and very much am the "little" guy. I showed at Nationals only this year, started with some B's on the string and only had enough money to do one so went R this year. I fit well, not trainer well, but hold my own locally with trainers in open classes. That said Nationally Ammy classes are a bear, the amount of trainer horses has likely more than doubled. It use to be the association with the most trainers was AMHA but as the pendulum swung from small to tall more and more crossed over to now I would say 90-95% of the top trainers do both. You would be surprised at how many Top Ten, Top Five and yes even National Champions get the gate in Ammy every year at Nationals.
Out of curiosity I counted 40 some trainer horses that took the top ten spots in the six Amateur classes at Nationals. I didn't even count the very, very good amateurs such as Erica, I only counted ones I knew were with trainers. It's not an exact count as I knew some were with trainers even though they were not listed, some I'm sure I missed. At a local level I don't know how much it matters, pick AMHA//AMHR what ever is easiest.
The AOTE is not perfect, it's flawed in the fact that it count's largely on people to behave in an honest, forthright nature and that doesn't always happen and that is not an association thing, it's a decent human being thing. While not perfect it does offer an alternative. Local shows likely will not break down level 1 and level 2 but they are there at a World level.
I had to go and look at the show number break down, I'm not going to count each horse but did count several classes under numbers and over numbers. Amateur classes had 182 unders and 169 overs, Futurity had 104 unders and a staggering 218 overs, Open had 416 unders and 344 overs. Halter counts for almost 60% of all entries so I didn't do any performance figures, they are there if you want to look. I did not count model, color, owned/bred/shown or any of those classes either. Safe to say it fairly close to a 50/50 break-down.
I love both AMHA and AMHR, but asking this forum "how to fix" AMHA is a lot like asking the Democrats how to fix the Republicans or vice versa.