We have had a very similar approach, again influenced by "Baby Wise", with good success. Not as impressive as your own, and we've got slacker with the younger children, I have to tighten things up again, but certainly I agree completely with this way of doing things.
Another example of training: We start training firearm safety once children can crawl. The reason being that when you're visiting someone, out here in the country, they might crawl and find an interesting toy under a bed (however many laws there may be about locking up guns, it doesn't necessarily happen). Put a gun (unloaded obviously) in the middle of the floor, say it's dangerous and they're not allowed to touch it, watch them very carefully and reinforce this until it is absolutely clear and they'll play all around it giving it a wide berth. Then occasionally reinforce it by just standing an unloaded gun in the corner of the room and checking they leave it alone. As they get older, if they are losing their appreciation for the danger of guns, get the noisiest one you have (ideally a shotgun loaded with birdshot), take them outside, fill a weak container with water (like a plastic milk bottle), and shoot it at close range. The shockwaves on a full container will make it explode in a dramatic fashion, and the pellets completely tear up the plastic. Ask them to imagine the container was some kid's head. An appreciation of the need for gun safety is guaranteed to be stuck in their minds for several years afterwards...
The point of training is to prepare people for a situation before it arises, rather than reacting to what they did wrong afterwards. Training gives them tools and confidence, it is a positive thing. Too many people expect their dog to be smarter than their kids, as they'll carefully train their dog but think their kids will just misbehave and that's just what kids are like.
If it comes to this point, don't undermine your wife's position in front of your children. Wait until you can call her aside or get alone and get a few minutes for clarification and teaching. To undermine her in front of the children or other adults will do more to tear down your house than to build.
I have a slightly different approach. I make it very clear in our house that I'm in charge, Sarah's second in command but under me, and the kids are under her. They understand this hierarchy. This means that if I override Sarah (which I do very rarely), I am not undermining her. Rather, she is demonstrating submission to authority, and they are to learn from her submission to me that they in turn should submit to her. So this can actually become a positive illustration, provided your wife knows the need for a positive illustration, so submits immediately and it doesn't become an argument (which would obviously be completely unproductive in front of the kids). If she disagrees, she can still go along with what the husband said at the time, but can then discuss it later in private. Although I very rarely need to override Sarah, as we are very much in agreement on most things, if I feel the need I don't hesitate to, because I know she will calmly support my decision and the children will learn a great deal from her humble example.
If you didn't run your marriage as a hierarchy but as a partnership, or if you were trying to have a hierarchy but your wife was not completely on-board, then I'd agree. Don't undermine her in front of the kids and cause an argument. But I'd see that as a fallback option only if she were not going to submit and give a positive illustration to the children, which in my mind is a better object lesson.