You have brought up a good point here horsewatcher and the fade bit and being swamped by the field is often true.

However, I'm talking another kettle of fish. What is usually happening in what you describe is in races with more than one leader who end up knocking themselves out up front setting the race up for the mid-pacers and or backmarkers.
If it is a lone leader who is swamped, it's almost always because it is being ridden by a [usually an inexperienced apprentice] jockey who is a poor judge of race pace.

Put a good senior jockey on a lone leader and there is no way the horse will knock up over the distance. In fact the jockey will slow the race down as much and for as long as possible [not good for backmarkers who need the pace on], and then just sprint away from the turn and be hard to catch over the short distance left to the finish post.

Anyhow, in the list of horses I've tagged on the previous page who race today, the ones marked [L] leaders are all lone leaders in those races.
The potential is there for them to win due to the tactics I've described. Of course there are many reasons they might be beaten too. The potential for the jockey to control the race pace though [a big advantage], won't be one of them.

The selection list is not from studied form on those races, they are just all the horses from the three cards who have the unique conditions I am talking about: More than one leader in the race for the backmarkers mentioned and being a sole leader in the race for the leaders I've mentioned. No other criteria at all. Took me about 15min. to do the list.