Why are there different manual movements in the new Dark Side lineup?

As the title says, we got a few cool Dark side watches out. There are quite the variety of movements along the line, with an automatic movement and 2 different manuals.

I really like the Gray Side caseback, showing off the modified 3861.

So I am a little confused why Omega picked a different manual movement for the "Dark Vader?" It seems like it's more a "detuned" 9900.

https://www.omegawatches.com/en-us/...ronometer-chronograph-44-25-mm-31092445006002

https://www.omegawatches.com/en-us/...ronometer-chronograph-44-25-mm-31092445101001