Okay, so I'm re reading this thread, and I'm a little confused.
You've been training the dog for 3 months, but you've had him 7 years.
In those previous 7 years, the dog never left the yard, but now that you have moved there is a need to walk him.
For a month of those three months you've been doing what you were told by the trainer from the site you posted.
You've attended two classes at the trainer's location.
Your dog behaves better at the trainer's location than out on a casual walk and you would like to know why.
Please correct me if I'm understanding wrong above.
There are several factors at play here.
The biggest factor is a dog who has lived with you for 7 years under certain rules and expectations, and now you are changing the rules. All dogs have a history with their owners and expectations of behavior whether we consciously teach them any or not.
He has spent his entire life in one yard, and now he has to navigate a walk in the city, which I imagine is overwhelming enough. But add to that that he has no training and doesn't know he can trust you or how to defer to you for guidance. Its like you've thrown him in to the deep end of the swimming pool without teaching him any basic water skills.
Following the water analogy, I'd be really interested to know how he acts (other than compliant) when at the trainer's place. You say he shakes and tucks his tail, does he also drool a lot? Shed a lot? Sniff the ground or hold his head low? Look away from you or the other dogs?
My guess is that with such close proximity of so many dogs, he is actually flooded, he is getting so much stimulus that he basically shuts down and goes in to a sort of mobile catatonic state. So while he's not exhibiting any "problem" behaviors, he's also not learning any coping skills either - as you have experienced as soon as he sees another dog outside of the environment of the training field.
The biggest thing this guy needs to know is that he can
trust you. That he can trust you not to put him in a situation he's not ready for, trust you to give him clear directions, and trust you to handle things so that he doesn't have to.
However you decide to teach him commands, it has to be in a way that is clear to him, that allows him to think for himself, and that builds his trust in you.
If you were pinged with a rubber band every time you gave the teacher the wrong answer, while its not really that painful, after enough repetitions, you're going to stop trying to answer and you're not going to trust the teacher very much either are you? (Or if you're of a particular temperament you might be tempted to grab that teacher's $%#&*$% rubber band and do some "pinging" of your own. *whistles*)
But if you got a smile and m&m's every time you got the answer right, you're probably going to keep trying even when the problems get more complex and difficult.
I find this statement on the website you posted very telling:
this type of training goes beyond “sit and stayâ€. A bond begins to form between a person and their dog. Training that does not need a treat or the sound of a bell or clicker or ball to drive your dog to do what you’ve asked of it. The dog will give 150% not sometimes, not half the time, but all of the time solely for that bond. They are more than happy to please us for a simple pat on the head or “good job†or “thank youâ€.
There is so much wrong here I don't even know where to begin.
a) ALL training that's worth anything goes beyond "sit and stay". ALL training that's worth anything creates a dog/handler bond.
b) the bolded part is total baloney and betrays a lack of knowledge of motivation in dogs (or people for that matter). Jean Donaldson explains it best in "The Culture Clash". That basically dogs work for two reasons, to gain something good or avoid something bad.
I don't understand how someone can train a dog with leash corrections and then say the dog is motivated to please you without also acknowledging that the dog is motivated to AVOID the leash correction. Dogs are no dummies and quickly learn that happy face on owner = no corrections.
Seeing as dog training is so dependent on understanding what motivates each individual dog, I'd be very leery of any trainer that had such a poor concept of motivation.