Yes and dogs can be classified as high drive but on different levels, like a border collie VS an american bulldog, both potentially high drive breeds with different drives.I think that one's understanding of "high drive" also has to do with experience. The spectrum against which we can actually place our own dogs. I know my thoughts on my dogs drive levels, Dylan in particular, have changed dramatically since I have seen a ton more dogs in the last year or so. I used to think D was high drive :lol: but really he's nothing special, just a pet who happens to have enough drive that it allows him to do the work at a low to mediocre level.
I think horse will have drive enough to allow him to participate but not anything compared to a well bred GSD. I am not expecting anyone to be blown away by his drives but I think he will do OK and its a foot in the door and the next dog will be better.
Experience can tell you a lot of things that reading all the books or websites will not tell you.