At this point, I don't believe there's any agreement on which of the "alternate" delta e formulas to use. Tolerances are assumed to be "straight" dE (dE76). Off the top of my head, I believe the tolerance MUST be below 5 dE76 for solids and SHOULD be below 3 dE. Grays I believe should be < 1.5 dE.
Assuming these are the correct dE tolerance values, they only work for dE76...you must lower the tolerance for either dE94 or dE2000. There's no hard and fast rule for this due to the complexity of the dE2000 formula but I would expect dE2000 tolerances to be roughly 2/3 to 1/2 of the dE76 values....as a guess. dE2000 is generally more sensitive to delta L* and delta hue than it is delta chroma.
Regards,
Terry