I finally got the time to read through Final Sanction last night to see what all the hullabaloo was about and one of the things that I paused and read multiple times was the whole Horde/Turning Point thing. It's interesting, but as presented—and I'm not saying that this is bad!—it almost felt like it could have been helped along by a flow chart/decision tree.
Thus, you start with "Conflict A" which moves along for n rounds until "Turning Point Z" occurs, at which point the Marines are met with a Challenge of a given duration (representing the tides of conflict and capitalising upon those). Resolution of Turning Point Z leads to either Conflict B or Conflict C depending on whether it is successful or not. If, for example, Turning Point Z was the massing of Rebels that needed to be broken before they could overrun the barricades, success would mean that the attack was defeated and the barricades preserved, while failure might mean the Marine's Horde (the PDF in the game) is reduced in Magnitude...
...Actually, that does raise the issue of whether there are Horde vs. Horde mechanics etc. in the final game. Irrelevant speculation perhaps, but seems like something that would be useful...
Conflict B is the successful resolution of Turning Point Z, so might allow a counter offensive by the PDF. Conflict C means that the Rebels have penetrated the lines and... Well, need those Horde vs. Horde rules. Turning Point Y, on the other hand, might be the Marines leading a heroic charge... Etc., etc.
You can also have "Blind Turning Points." For example, if a Marine sees the Rebel offensive of the barricades, they might make a Strategy test (or whatever) and have the PDF centre pull back from the barricades, allowing the Rebels to penetrate, and then flank the Rebels to cut them off and deal with them. (Again, might need those Horde vs. Horde rules for this traditional "horn of the bull" approach.) Thus, rather than Conflict B or C, they throw it into Conflict D which has resulted in a major reduction in the Magnitude of the Horde.
Obviously something that can be done on the fly in reaction to the players, but mapping it out as a flowchart might be a rather useful tool to develop. That and those Horde vs. Horde mechanics. Especially if you can break a Horde into separate elements that might be individually commanded by "Hero" elements such as the Marines.
Just some random thoughts. Guess I'm going to have to wait and see whether I'm going to have to include this type of thing in my own interpretation (i.e. the "Magnitude," for want of a better term, of a Single Mode Marine, a Squad, etc.)