Waldo1
I don't think you can point the finger at GAL procurement. The ground handling companies have no contractual relationship with GAL, other than landlord and tenant type arrangements. Under the 1996 EU directive on ground handling, airport operators are severely limited in their ability to limit the numbers of ground handling companies. If a number of airlines choose to use a particular ground handler, it would be a brave/foolhardy airport operator to try to prevent it.
Clearly the issue is that airlines' natural attempts to reduce costs, coupled with a highly competitive handling market, have led to a situation where Swissport bought a lot of business without adequately resourcing for it. There's not much an airport operator can do to interfere in such a process, without falling foul of the 1996 EU directive.