If a dog came up to me and started speaking plain english, I may be a litle surprised at first, but then I would listen and communicate with the dog. If multiple dogs started to speak english to me, then I would not be too surprised anymore and communication with dogs would come naturally.
When it comes to horses and NH, horses already speak the language, they do not have to be taught it. What they have to get used to is the idea of listen to the dogs speaking english (us). I commonly find that during beginner lessons, my lesson horse is checking with me about what to do next because whoever is on their back is still a little rough with the language. All the extra "fluff" is simply a matter of time, consistency, and pressure and release. Horses are naturally going to be pulled to the safety of the good leadership of a confident human that is "speaking clearly". That leadership ability is commonly overlooked, thinking that the horse is simply learning to respond to cues. Actually, in many cases, the horse is just learning to respond to cues, this is why you see a lot of NH trained horses that will climb on top of their scary obstacles, stand to have a giant ball bounced next to them, and allow a tarp to be thrown over their back, yet they still can't walk by a scary looking rock on the trail.
I have personally seen many times how people see the result of training and thinking that simply practicing that over and over again is how you get there. For example, my own horses are used to standing quietly ground tied when I jump off and do something else. I can't tell you how many times I've seen people see me do this and just assume that if they try it, their horse will do it too. It always ends up with some horse running off, and that is not with me trying to show off, its just something I do all the time without thinking.
I know someone else that is starry eyed over liberty work. She takes her horse in the arena and lets her go and continuously tries to get the horse to run with her, which always ends up with the horse running around screaming to all of the other horses outside of the arena.
My advice, don't look at the "tricks". The 16 yr old kid that wants to race his car without first learning respect for what the car is capable of is going to end up hurting himself or the car. Focus instead on being part of their world. In other words, your goal should not be to get the horse to be obedient, your goal should be for you to learn how to communicate.