The autosave and quicksave are prone to corruption and are best avoided if you're getting problems with savegames refusing to load.

The pre battle save is as much of an exploit as the pre battle screen itself. The shuffling of reinforcements is something that the AI cannot do, it has to go into battle with the starting line up that it's given (this is how it worked in MTW 1.1 and in STW). I find that if I can shuffle my reinforcements around and dismout my troops, I can win any battle. I've won battles against the GH in this way when outnumbered three to one. I had mostly spears, bows and arbalests with some flanking units and fast cavarly in the starting line up. My archers were queued up in batches to come on when required to replace those that had run out of ammo. Replacement spears would be well down the list as they are needed later. I would have batches of cavalry and flankers in between the missiles to replace tired units. When you have this kind of organisation and you're camped on a nice hill, taking on the GH is a turkey shoot. This is why I'd add the "pre battle reinforcements shuffler" to the list.