Yes Mike the in-tank pump will supply some fuel but not at any significant pressure, certainly not enough to run the car.
The Freelander although it uses a flat tank just utilises the same fuel delivery system as the early 75. The ECU's were set up for two pumps so that what they got.
I've looked into the tank on both sides with early cars that have a failed in-tank pump and there's quite a difference.
The interior tank pipework is totally different in the later models with a single pump so the problem with differences in tank level can't arise. You can't change over a early car to single pump without changing the tank and the pipework
Russ