Running 2 pumps I would think just gives more flow for when the engine needs it ?

I doubt the pumps would be inline of each other though.

Some race cars I have seen run 2 pumps, sometimes for safety though so IF one failed then could still complete the stage or get back into the pits rather than have to retire.

In your case one 044 simply cannot supply the amount of fuel needed on full boost when 2 ofcourse will easily cope with it.