Good structure put in place. Hard to gauge how aggressive the dog really is. A little bit of halfhearted barking on leash doesn't seem like very much.
I feel the structure and methodology overall is good. It seems he's worked a good variety of stimuli over the course of the three weeks. Though it's hard to tell much more because it's just before and after, so we don't see the training in progress or see how exactly he is structuring reward (if any), punishment, markers, or shaping new behaviors.
As long as it is practiced consistently, I'm sure it'll last long term. And it is something that would probably work on many dogs. But I would never say any one method would work for every dog.
Same structure can be applied with other training methods. I've done the exact same thing with marker training. Though I feel like I end up with a happier, more comfortable dog. The bulldog's body language does seem a bit suppressed to me.
Overall, it may be decently done. It's hard to say because I can't see any of the work in progress. I am resistant to go to aversive methods if I feel there is a potential answer in positive reinforcement, especially when it is about reactions to dogs/people. So I can't say I'm super happy about the use of the ecollar from a personal standpoint. But from a professional standpoint, it seems well done from the little that I can see.