Fuji had three different double coatings for some time around the 90s.

The "lower" quality was used in KII, JPII, DRII (there were also DRII with single coating)
The higher quality : FRIIx, JPIIX, Z
The top quality : ZII, JPIIpro

On Fuji, someone once wrote that the difference between JPII and JPIIx is only in the qualifying class, so Fuji actually only made two Type II tapes, but he also found this in some old magazine in a test.
We know that the information is different.

Difference between JPII and JPIIx is +1.5db in MOL
Difference between JPIIx and and JPIIpro is 4µm vs 5µm in coating thickness.

Possible... three different double coated tapes is somewhat strange... but all we have is the datasheets.
Maybe they somewhat "stretched" the numbers to make up those three quality classes.