Yes look at them all of course. But try to get certain ones as close as you can and then make the others relative to those benchmarks, using common aero performance sense. I think PF has most certainly shown you can't get everything right everywhere for every plane and that is with a lot of original source test reports, etc. Precious little of that remains from WW1 planes. Also, I think given the variablity in WW1 numbers it is pointless to try to get everything on-spec since you can't even tell what spec is for everything for every plane.

Let's take the Albatross series. All are basically the same but with different engines. Make an effort to get one of them like the DIII as close to whatever is decided is "spec" then make the DII and DV/Va relative to the DIII, a little slower or faster in top speed and climb. But don't make a huge effort to try to get them all on spec since you'll get all wrapped up in what spec is when all that really matters is the one that is a little faster in reality is a little faster in the sim. Who cares if in reality some source says is was 5 mph faster and the sim gives 3 or 7 mph? I'd much rather that the relative performance is correct and that it is all in the right direction than having something on spec in one or two parameters but all hosed up somewhere else just to satisfy some misguided thinking.

I'd love to see this wealth of data since I think it doesn't exist because if it did then RB3D wouldn't have turned into the stupid FM forum fights and the multitude of 3rd party FMs all of which were based on some data but each was very different.