I have ponied horses over water because the rider couldn't make the horse go over. IMO, when its a horse that you know will cross water it just "is not in the mood" it works well with or without a rider. But, the times I have "pulled" a horse that would not cross the water because of a lack of experience, it didn't go well, Last time I tried it the horse I was ponying ended up under the horse I was riding.
After that I really have been thinking about how much it really helps to pony a horse through a trail obstacle. If, its as we have been saying a "training issue" then pony a horse through a obstacle really isn't "the best". Does ponying teach the horse to obey its rider and to move forward into the obstacle? I know you got to get the horse through somehow, otherwise what do you do? Leave them there alone? Or does the ride end just because one person can't get their horse into a creek, or over a log, or onto a bridge? So we "pony up" and pull the horse through the issue. BUT, what does the horse really learn? I think the important part never really gets worked out the horse never goes back home for training/re-training. The "rider" thinks we ponied them through now they are good. Right? I have to admit, there have been times when this is how and what I have thought.
We have to remember, like you all have been saying, having a problem with a obstacle is only a symptom of a gap in training and really the way to fix that gap is to train/re-train. That training can happen at home in a round pin, arena or out on a trail ride. BUT, training doesn't just happen it takes being intentional with when, where and how we ride and how we deal with trail obstacles and the opportunity they provide.
Thank you all this has been a really good exercise for me to think through. This is why I really like this forum, it helps me think through the how and why of my training having to put my thoughts into words (sometimes not the best word) really forces me to look at my training methods. And really until now it was something that I didn't do nearly enough.