Hey Angelo,
I have read the thread and have to agree with the others. Perhaps barring a release by the VI Magazine guys I could send you Thomas J's article regarding relative dynamics in order to illustrate our point. In the article he accurately describes just how important this is. His piece 'Mojo Madness' serves as further proof of just how critical this is to achieve realistic mock ups.
Rather than debating though the artistic/scientific integrity of a template I think it stands to reason to try to gain a rough estimate. As of now I and apparently others have been unable to find even the slightest documentation in this regard. I understand how many variables are involved when recording and mixing an orchestra. I know that nothing can stand as THE template but even a rough guide is a huge step in the right direction. Once a rough guide is established one can deviate as needed while always having a safe zone or as you put it 'guideline to avoid the chaos'.
I think the proof is in 'Mojo Madness'. One point Thomas J makes that is very interesting is that most if not all orchestral sample library's are normalized. You already brought this up by saying a PPP articulation is the same loudness level as a FFF. This is why if one were to simply measure the FF of a tutti and write from that your orchestra would still be horribly out of balance. He goes on to illustrate more complex issues such as the flute being louder in one range and softer in another. 1 flute playing and 3 flutes playing etc. He does offer Expression loudness adjustments for such occasions which was helpful. I think for now though the complexity of those issues can be set aside and one can focus purely on the maximum loudness of each instrument.
If you knew the maximum volume of each orchestral instrument in its normal context/setting (debatable again but evaluating every variable stiffles all but the smallest of progress) than you could use a simple mod Xfade patch to determine the dynamics of the instrument once the fader is set correctly so that the samples maximum loudness matches that of the said chart we would like to create.
As I said and I'm sure Thomas J anticipated you will ALWAYS have the science/engineering/orchestration nerds who will come forward and throw this down as idiotic or nonessential or only 'theory'. I could see the point but Thomas J has alreayd put the pie in those peoples faces. Mojo Madness is proof that this needs to exist on some level.
If anyone has the means to make this happen or know where we can find the data please call on donations or something. This would benefit the entire orchestral mock up community greatly.
Rob