BALPA were quiet about the whole Atlas wet lease - no doubt under pressure of the BA management. It was the IPA which pushed the case and the real reason why GSS was started.
I don't know the extent of the IPAs involvement but BALPA were hardly quiet about it. They were certainly protesting to BA about it, which hardly fits with the 'BALPA in BAs pocket' theories.
This isn't how ACMI wet leases work. The freight work was outsourced - as it had been for years. The only case BA pilots had was now that the freighters using Birdseed call-signs now had G registrations.
The issue was not how ACMI wet leases work, it was about how BA pilots' scope clause worked. The BA pilots view was that ACMI leases of dedicated aircraft for exclusively BA work, be it pax or freight, was in breach of Scope.
don't see why. GSS had been running for a few years before the secondee situation emerged. They didn't need them, and many in GSS didn't want them. Interestingly, BALPA supported the secondee proposal - perhaps as a bit of a F you to the IPA having had their nose put out of joint in 2002. Knowing ES, I suspect he really didn't care where his captains came from, but was quite happy to go along with a plan from his mates at BA.
GSS running without the secondees was akin to a tax loophole. They got away with it for a while but the loophole was eventually closed. GSS didn't need secondees and ES fought tooth and nail to keep them out. It was BA who needed the secondees to keep the wheels on the wagon. No secondees would mean no deal with their own pilots and that was a more pressing concern for them than shipping a bit more freight, especially as the cost to BA was negligible. With only one customer GSS just had to lump it.