Hey Adrian,
As I mentioned in my updated post, I'm now passing data by use of a class variable common to both Service_A and Service_B
Without more information on the relationship between the service objects it's hard to tell. Can you show what/why Service_B needs Service_A's test results?
I don't think that should matter. This test suite is for the Google::Adwords module. When I run the sandbox tests for, say the CampaignService test module, I then require the campaign ids for use in the AdGroupService test module. These are only for the sandbox tests, and I can test the various service modules independently otherwise.