That makes more sense they tried to start the APU and get the APU gens on line.
Boeing ops manual says apu in flight for pneumatics only,
Many APU on the 747 are locked out and will not even start in flight.
Dont blame them would try anything at that point since the airplane is only being powered by essential standby bus with loss of all gens.
Had that problem a few years ago, maybe not the same as what they experienced.
Left the bus ties open and at least got one gen back on line.
I am sure the crew tried all of this.
Good they landed safely, tires are cheap, lives are not!