Apples, I think your cautions are a great illustration of the difference between just following a training 'recipe', a set of instructions - trying to emulate 'methods' without full understanding - compared to understanding & using *principles* of training theories. Just like with hoof care - or probably almost anything else - if you try to just follow a 'recipe' approach, colour by numbers, you will come up with many instances where it doesn't work/isn't right. But if you can understand the *principles* & reasoning behind the specifics, you can generally work out how to adapt your 'methods' accordingly, to fit the specific situation or horse.
while books and videos can be helpful for some horses, every horse has a different way of learning or processing information,
I agree with behavioural theory, that ALL animals - no matter what species we are - learn in essentially the same way - that is, what 'works' for us, what is profitable to us, we will learn to do more of, while what never profits us, what may be 'bad' for us, we will do less of. That we learn by associating actions with consequences. Just that, other animals, not having a verbal language like humans, to be able to link abstracted ideas(like delayed punishment/reward for eg), need more *instant* association of cause & effect. And all animals - be in species difference or individual... or even the same animal at a different time/situation, will have different perceptions about stuff & different motivators - eg. sometimes even minis & labradors won't be interested in food treats!
So we need to understand 'what lies beneath' in order to know what specifics may or may not be best at any given time.
Also, PLEASEEEEE donít clicked train your lil one to pull a cart!! I cannotttttt stress this enough. Although itís good for tricks, a horse should not always expect a treat when in the cart. Many of the horses Iíve seen this done with have either not been able to pull a cart, would be dangerous in the cart, or would refuse commands after realizing they canít always have a treat when someoneís behind them in a carriage.
I think this is also a matter of whoever was doing the training not understanding the principles, so not training *well*. Regardless of whether you're teaching 'tricks' or anything else, horses should definitely not 'only work for treats' - IOW be rewarded/expect a handout for everything they do. If they have not been taught properly, if you've inadvertently taught them you're a vending machine, then it is the fault of the trainer, not the 'tool' or the activity being taught.
The other bit about this is, while some are 'purist' positive reinforcement trainers, probably the vast majority of us use c/t or rewards in conjunction with other training. So for eg. I just incorporate rewards as part of the 'whole picture' & my horses still learn to respond to reins, negative reinforcement, etc. I do think it would be rather... dangerous & probably not all that efficient to teach a horse to pull a cart or be ridden *solely* with positive reinforcement training.