Thank you for being so patient with me. One last thing, if you don't mind. I'm still not clear on the t maps. I'm not even sure what they are, and google doesn't seem to have a clue either. I made something that resembled one, but it crashed my game and gave my graphics card some kind of fit, so I'm guessing whatever I did was not what it was looking for.
_t maps are essentially tint maps, as adela said, it controls the global look of an object.
Thought of it, but if you swap the red and blue channels around then their 'style' still doesn't quite match how the red and blue is done for the other items, plus the regular shader wouldn't automagically know it should use the channels in different order, so... it kinda boils down to the same thing :3
the alpha for Flemeth is shaded so I don't think it's just a mask, it looks more like the diffuse (or specular, I'm still not sure which one it actually is) data placed in separate channel for whatever reason.
The alpha in flemeths specular texture is just an alpha mask, not even sure if its used, its just the same as the diffuse one. Looks like they may have used the diffuse texture as a base to make the specular texture and the alpha was just left in there.
As for allistair and why he is different, im going to say the same as someone else did earlier, iteration, they probably tried a few different ways, and some actors/objects got left the old way, odd is the fact it doesn't use a different shader from what i can tell.