An interesting observation, I'm going to have to study this.
When the Gulf War kicked off, British troops weren't able to use their own camouflage (1980s 4 colour Desert DPM) and so deployed wearing temperate DPM. Some bright spark in the MoD had previously okayed sale of Brit uniforms (4 col DesDPM tropicals) to Saddam Hussein's Republican Guard.
If it didn't prove confusing to UK Forces, we certainly would have suffered more "blue-on-blues" from are allies than we did.
The DesDPM (1990s 2 colour) that we're familiar with started out as a rush job. I read in a 1990s magazine (I think "Military Modeller") that there were something like 7x different DesDPM patterns (by the time of writing or actually worn on Op Granby).
I'm wondering if the brief to manufacturers were along the lines of "We need a desert version of DPM but in these 2x colours (brown/beige). See what you can come up with. By the way, we need it yesterday."
Speculation but it'd explain why there were so many variations in the print. Is there a way to match print with manufacturer? I'm wondering if there were 7x different manufacturers...