I'm glad you enjoyed it. :) I spend a lot of time by observing herd behavior and then trying to mimic their "dances" in my moments with Snickers. I still don't get many things and I have to learn to be a better "lead mare", and also I have to keep things interesting for Snickers (his main motivations are learning something totally new and pride), and also my body language could be much, much better, but heck...it's a learning process for both of us.
I believe that you could do this all without treats with Zulu, you'd just have to start from the first steps to reset Zulu's motivations and prove him that doing things with you can be very interesting even without snacks. :) It really takes time, of course. I wish I could spend every single day with Snickers and maybe then I'd have enough time to do both riding and groundwork as much as I want it.