Just to complete the answer. The issue and the work around is documented in the Product Anomaly Notice for the nRF8001. See Anomaly#4 in the document.
You can move around the GATT Service order by moving the service, i.e. moving all text from and including and tags in the XML file.
Verify that the order has changed by looking at the ublue_setup.gen.out.txt (Which is generated when generating the services.h/services_lock.h from the XML file using nRFgo studio)
I do no want to "pollute" the forum with a non-question topic, and given my announcement is very related to this topic, I'll post it as a comment here.
Some weeks ago I began analyzing the format of nRF8001 setup messages, and I think I made enough progress to make my "work in progress" public. So far I have a Python script for showing byte-to-byte differences between setup data from two nRFgoStudio reports (i.e. those ublue_setup.gen.out.txt files created when generating services.{c,h} files) and another tool for extracting the setup data from the report file and dumping it in human readable format.
Note that my goal is not to write a full featured tool like nRFgoStudio, but simply to fully understand what happens "under the hood" during setup. That said, anyone is free to customize the tool for other purposes.
My short term plans:
finish analyzing the remaining fields (i.e. those related to pipes and 128-bit UUIDs).
write more tools that help analyze the message format
