Picking LHR as an example.....
Do we really think BA will employ any more tug drivers? They don't employ enough dispatchers as it is, and it's getting worse (and how does the increased wage bill compare to the money saved?).
How does GMC cope with the fact that a/c (especially fully laden 747s) tow much slower than under their own power?
Who does GMC talk to? The cockpit? The tow crew? Both? That's just far too confusing!